29: Echinoids of Georgia
Cenozoic Era
(Sand Dollars & Urchins)
By
Thomas Thurman
December 2023
This page dedicated to
Dr. Paul F. Huddlestun &
Dr. Buchard (Burt) D. Carter,
Scientists I’m proud to name as
friends & advisors.
The Cenozoic Era began 66 million years ago with the demise of most dinosaurs and continues today.
In 1959 Wythe Cooke, working for the US Geological Survey (USGS), published the research guide Cenozoic Echinoids of the Eastern United States, and it still stands as one of the most influential and important geological publications for the East Coast. My hard copy was a gift from Paul Huddlestun, he stuck a post-it-note inside saying “This should help! Paul”
Yes, it still helps, Mr. Paul, maybe I can pass your assist along.
In 1959 Wythe Cooke, working for the US Geological Survey (USGS), published the research guide Cenozoic Echinoids of the Eastern United States, and it still stands as one of the most influential and important geological publications for the East Coast. My hard copy was a gift from Paul Huddlestun, he stuck a post-it-note inside saying “This should help! Paul”
Yes, it still helps, Mr. Paul, maybe I can pass your assist along.
Echinoids are members of the echinoderm phylum, which includes urchins, sand dollars, sea cucumbers, sea stars, and feather stars (crinoids). But generally, when speaking about fossils and for our purposes here, “echinoid” refers to urchins and sand dollars which are easily, frequently, and usefully preserved as fossils.
Even “sand dollar” is little more than a descriptive term for a flattened urchin. Sand dollars, sea biscuits, sea urchins, heart urchins are all variations on a theme produced by evolution as these animals adapted to different environments and lifestyles.
Because they evolve quickly, radiate easily as free-floated embryos, and readily preserve as adults, echinoids are valuable index fossils. They can often tell you the general age of their host sediments. Cooke was straightforward about this; “Echinoids are exceptionally good horizon markers because of their short geologic ranges.”
Sea stars and crinoids both fossilize from time to time, but not frequently enough to make dependable index fossils.
Using the 1959 report from Cooke, all you need to do is identify an echinoid by the images he published and you can roughly date the sediments hosting it.
For this webpage, I'll report the echinoids Cooke listed as occurring Georgia and note his locations at least to the level of county. From there I overlaid the extensive later research of Dr. Burt Carter (Professor Emeritus Georgia Southwestern), Dr. Paul Huddlestun (Retired Georgia Geologic Survey) and the 2017 research of Louis Zachos from the University of Mississippi.
I then used the online reference catalog of the Florida Museum of Natural History.
I then used the online reference catalog of the Florida Museum of Natural History.
Florida Museum of Natural History
Abbreviated as FLMNH
Many species and sediment formations have been reassigned since 1959, and Florida Natural History Museum (FLMNH) is actively reviewing echinoid nomenclature, so whenever possible I have searched and listed the current nomenclature and noted it’s source, usually this was the online directory at the FLMNH. The Florida Museum holds, maintains, and researches the largest collection of fossils in the southeast. Their web portal was invaluable fore this project; Web Portal (ufl.edu)
Species & Sub Species
As in many fields of paleontology, there is ongoing debate about several species and genre of echinoids. At what point are features simply variations within a species or grounds to establish a new species? Dachshunds (20lbs) and Saint Bernards (200lbs) are both members of the same species Canis familiaris, the domestic dog. But in paleontology we need the ability to differentiate between species at a relatively fine scale to understand stratigraphy and evolution.
Many modern researchers question Cooke’s definitions of species and suspect that some are merely natural, perhaps even localized variations within a single species. There is wide natural, localized variation within our own species. So these scientists certainly have a valid argument.
Nevertheless, no other general echinoid research guide has yet been produced by the paleontological community in 64 years. Cooke’s 1959 paper is what we have. I understand that the Florida Museum of Natural History is working on this, but nothing is yet published and may not be published for months or years.
Therefore, this page is based on Cooke’s 1959 research, and I have updated it as best I can with available materials.
As in many fields of paleontology, there is ongoing debate about several species and genre of echinoids. At what point are features simply variations within a species or grounds to establish a new species? Dachshunds (20lbs) and Saint Bernards (200lbs) are both members of the same species Canis familiaris, the domestic dog. But in paleontology we need the ability to differentiate between species at a relatively fine scale to understand stratigraphy and evolution.
Many modern researchers question Cooke’s definitions of species and suspect that some are merely natural, perhaps even localized variations within a single species. There is wide natural, localized variation within our own species. So these scientists certainly have a valid argument.
Nevertheless, no other general echinoid research guide has yet been produced by the paleontological community in 64 years. Cooke’s 1959 paper is what we have. I understand that the Florida Museum of Natural History is working on this, but nothing is yet published and may not be published for months or years.
Therefore, this page is based on Cooke’s 1959 research, and I have updated it as best I can with available materials.
A Bit About Echinoids
Symmetry
You and I have bilateral symmetry, we have two sides, our right and left side are essentially the same, mirror images. Larval echinoids also have bilateral symmetry, but many adult echinoids have pentaradial symmetry, they have five sides.
From a geologic perspective, echinoid tests (a test is the “shell”) are formed by interlocking hexagon panels. Each of these panels is a specialized, single, calcium crystal.
Symmetry
You and I have bilateral symmetry, we have two sides, our right and left side are essentially the same, mirror images. Larval echinoids also have bilateral symmetry, but many adult echinoids have pentaradial symmetry, they have five sides.
From a geologic perspective, echinoid tests (a test is the “shell”) are formed by interlocking hexagon panels. Each of these panels is a specialized, single, calcium crystal.
Regular and Irregular
There are two basic types of echinoids, regular and irregular, these are descriptive types only used generally.
There are two basic types of echinoids, regular and irregular, these are descriptive types only used generally.
- A “regular” echinoid is a typical sea urchin which ambles along the sea bottom on its spines with its mouth is downward, centered on the body, feeding on biologic matter which has rained down from above. It’s anus is on top, expelling and dispersing waste into the current and as far from its food source as possible.
- It has no left and right, no front or back; merely a top and bottom.
- Its spines are defensive, typically arrayed in all directions.
- An “irregular” has generally evolved toward burrowing. The mouth is still bottom center, but the anus (periproct) has moved to the rear or bottom some distance aft of the mouth. If it has spines (sand dollar do not) they are typically swept back to the rear, so they won’t interfere with forward progress while burrowing. They typically burrow just beneath the sea bottom, leaving waste in their wake.
- Irregular echinoids include sand dollars, heart urchins and sea biscuits.
- They are both bilateral and pentaradial.
- They have a front, back, left right, top and bottom.
- This gives them a direction of travel.
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An Urchin’s Life
Adult echinoids aren’t travelers like the larva typically are. At most they amble slowly along the sea floor or burrow along just beneath it, so how do the species radiate?
There are male and female urchins but they are indistinguishable, depending on the species they have 2 to 5 genital pores which produce and broadcast gametes in the surrounding seawater where fertilization takes place. In successful fertilization a free-floating embryo forms and these can travel with the currents, radiating with the species. At the end of the larval stage the animal sinks and metamorphosizes into an adult. But there are differences between the species and how the larva develops into adults.
Adult echinoids aren’t travelers like the larva typically are. At most they amble slowly along the sea floor or burrow along just beneath it, so how do the species radiate?
There are male and female urchins but they are indistinguishable, depending on the species they have 2 to 5 genital pores which produce and broadcast gametes in the surrounding seawater where fertilization takes place. In successful fertilization a free-floating embryo forms and these can travel with the currents, radiating with the species. At the end of the larval stage the animal sinks and metamorphosizes into an adult. But there are differences between the species and how the larva develops into adults.
Cooke 1959
Turning back to Cooke’s work, as an employee of the USGS he published two reports in the Journal of Paleontology.
I want to thank Dr, Christy Visaggi at Georgia State University for providing me copies of Cooke’s 1941 & 1942 publications. Visaggi is a marine biologist and paleontologist. She’s also a member of Facebook’s, Georgia’s Fossils Group. Visaggi also sent me digital copy of a pertinent 2017 paper by Louis Zachos.
Again, thanks Christy, the support is appreciated. I wasn’t aware of the Zachos paper.
Turning back to Cooke’s work, as an employee of the USGS he published two reports in the Journal of Paleontology.
- Cenozoic Regular Echinoids of Eastern United States, 1941
- Cenozoic Irregular Echinoids of the Eastern United States, 1942
I want to thank Dr, Christy Visaggi at Georgia State University for providing me copies of Cooke’s 1941 & 1942 publications. Visaggi is a marine biologist and paleontologist. She’s also a member of Facebook’s, Georgia’s Fossils Group. Visaggi also sent me digital copy of a pertinent 2017 paper by Louis Zachos.
Again, thanks Christy, the support is appreciated. I wasn’t aware of the Zachos paper.
*Echinoids of Georgia*
Agassizia clevei
- Current nomenclature
- Florida Museum of Natural History (FLMNH)
- National Museum of Natural History (Smithsonian)
- Erected as a species in 1875 by G. H. Cotteau
- Placed by Cooke (1959) as Agassizia (Anisaster) clevei, with Anisaster as subgenus.
- Overturned, Agasazia clevei stands as a current genus and species.
Agassizia clevei
Description
(To the level of genus by Cooke 1959)
Genus type species; Agassizia scrobiculata. (1846) by monotype, living off the west coast of tropical and subtropical America. A distinctive feature is the great reduction in the width of the anterior poriferous zones of the anterior paired petals. The pores are consequently very inconspicuous· The species has a peripetalous fasciole, which is marginal in front, and lateral fascioles. This combination might better be described as a marginal fasciole and a hemipetalous fasciole.
Occurrence
Late Eocene, Jacksonian Stage (Carter 1987)
Description
(To the level of genus by Cooke 1959)
Genus type species; Agassizia scrobiculata. (1846) by monotype, living off the west coast of tropical and subtropical America. A distinctive feature is the great reduction in the width of the anterior poriferous zones of the anterior paired petals. The pores are consequently very inconspicuous· The species has a peripetalous fasciole, which is marginal in front, and lateral fascioles. This combination might better be described as a marginal fasciole and a hemipetalous fasciole.
Occurrence
- Decatur County, GA (Carter 1987)
- Calhoun County, GA (Carter 1992)
- No Georgia specimens held by FLMNH
- 50 Florida specimens housed by FLMNH
Late Eocene, Jacksonian Stage (Carter 1987)
Agassizia floridana
- Could not confirm current nomenclature
- Possibly (probably) reassigned
Agassizia floridana
Descriptions
Horizontal outline obovate, truncated behind; upper surface strongly inflated, highest in front of the genital system; margin broadly rounded; lower surface gently convex. Apical system behind the center; four genital pores, close together; ethmolytic, madreporite extending between the ocular plates. Anterior ambulacrum very slightly depressed. Paired petals straight, slightly depressed; anterior pair twice as long as the posterior; both pairs diverging at an angle of approximately 90°; pores of posterior petals and posterior zone of anterior paired petals oval; plates of anterior zone of anterior paired petals small, pores very minute; interporiferous zones narrow. Peristome at the anterior third, large, reniform, weakly lipped. Periproct transversely oval, about midway up the posterior end, at the top of a truncation. Marginal fasciole curving downward below the periproct; hemi-petalous fasciole meeting the · marginal fasciole behind the anterior paired petals. Length of figured specimen 36.2 mm; width 35 mm; height 28.4 mm.
Occurrence
Descriptions
Horizontal outline obovate, truncated behind; upper surface strongly inflated, highest in front of the genital system; margin broadly rounded; lower surface gently convex. Apical system behind the center; four genital pores, close together; ethmolytic, madreporite extending between the ocular plates. Anterior ambulacrum very slightly depressed. Paired petals straight, slightly depressed; anterior pair twice as long as the posterior; both pairs diverging at an angle of approximately 90°; pores of posterior petals and posterior zone of anterior paired petals oval; plates of anterior zone of anterior paired petals small, pores very minute; interporiferous zones narrow. Peristome at the anterior third, large, reniform, weakly lipped. Periproct transversely oval, about midway up the posterior end, at the top of a truncation. Marginal fasciole curving downward below the periproct; hemi-petalous fasciole meeting the · marginal fasciole behind the anterior paired petals. Length of figured specimen 36.2 mm; width 35 mm; height 28.4 mm.
Occurrence
- Near Bainbridge (S.W. McCallie)
- Late Eocene
- This species was identified as Hemiaster conradi Bouve (1851, p. 3, 2 text figs.) by Clark and Twitchell, but according to H. L. Clark (Cooke, 1942, p. 45) the type of that species is "absolutely unidentifiable even to the family, let alone genus or species." Agassizia injlata Jackson, placed by Pijpers in the synonymy of A. conradi as identified by Clark and Twitchell, appears to be a synonym of A. floridana though its base is a little flatter, its peristome somewhat smaller, and its periproct somewhat lower; these features, particularly the location of the periproct, are obscure in the type of A. inflata. Both A. inflata and A. egozcuei are based on part of A. (Anisaster) clevei Cotteau (1875, p. 33, pl. 6, figs. 9, 10, not figs. 2-8) from which they differ in their more widely diverging anterior petals and in other features.
Amblypygus americanus
- Current nomenclature
Amblypygus americanus
Description
Test large; horizontal outline circular; upper surface more or less inflated; lower surface gently rounded, concave around the peristome and less so around the periproct; margin broadly rounded. Apical system central, with four genital pores; a large central madreporite fills in the spaces beside the much smaller genital plates; ocular plates small. Ambulacra narrow, continuous, expanded on upper side into petals with round inner pores and elongated outer pores; petals extending to the margin, inner pores forming a straight line, outer sides of petals slightly arched. Peristome subtriangular, oblique, wider Durhamella floridana
the peristome than the margin. Tubercles small, sunken; intermediate spaces and madreporite granulated.
Length of type of 113 mm, width 110 mm, & height 58 mm.
Occurrence
Geologic Unit
Remarks
Description
Test large; horizontal outline circular; upper surface more or less inflated; lower surface gently rounded, concave around the peristome and less so around the periproct; margin broadly rounded. Apical system central, with four genital pores; a large central madreporite fills in the spaces beside the much smaller genital plates; ocular plates small. Ambulacra narrow, continuous, expanded on upper side into petals with round inner pores and elongated outer pores; petals extending to the margin, inner pores forming a straight line, outer sides of petals slightly arched. Peristome subtriangular, oblique, wider Durhamella floridana
the peristome than the margin. Tubercles small, sunken; intermediate spaces and madreporite granulated.
Length of type of 113 mm, width 110 mm, & height 58 mm.
Occurrence
- Georgia: East bank Chattahoochee River above US 84 near Saffold, Early County.
- Early County, GA (Carter 1987)
- No Georgia specimens held by Florida Museum of Natural History
- 43 Florida specimens held by FLMNH
Geologic Unit
- Cooke, 1959, Late Eocene
- The Echinoid Database, Miocene, Caribbean and US (Natural History Museum UK)
- Late Eocene, Jacksonian Stage (Carter 1987)
Remarks
- The preceding description is based on Twitchell's type of Amblypygus merrilli. There seems little doubt that this species is the same as that occurring in Jamaica, although direct comparison has not been made. Amblypygus douvillei may be a synonym.
- The specimen from Georgia is smaller (length 85 mm) but has a wider periproct. Considerable variation in the proportions of the periproct and in the degree. of inflation of the upper surface is to be expected.
Anisaster mossomi
- Current Nomenclature
- Formerly, Anisaster mossomi (Carter 1987)
- Formerly Agassizia (Anisaster) mossomi (Cooke 1959)
Anisaster mossomi
Description
Horizontal. outline oval, truncated behind; upper surface greatly inflated, steeply sloping forward from the apical system, very gently behind; margin broadly rounded; lower surface moderately convex. Apical system central; four genital pores close together; madreporite extending far behind. Anterior ambulacrum weakly depressed; pores far apart. Paired petals moderately depressed; anterior pair nearly twice as long as the posterior, diverging at an angle of approximately 90°; posterior pair diverging somewhat less; pores elongated-oval ; anterior poriferous zone of anterior pair much narrower near the apex; interporiferous zones narrow. Peristome at the anterior third, transversely oval, moderately lipped. Periproct large, transversely oval, at the top of the posterior truncation. Marginal fasciole descending below the periproct; hemipetalous fasciole meeting the marginal behind the anterior paired petals. Length of holotype 27 mm; width 24.5 mm; height 23.4 mm. Length of figured paratype 25.2 mm; width 24 mm; height 22 mm.
Occurrences
Geologic unit
Description
Horizontal. outline oval, truncated behind; upper surface greatly inflated, steeply sloping forward from the apical system, very gently behind; margin broadly rounded; lower surface moderately convex. Apical system central; four genital pores close together; madreporite extending far behind. Anterior ambulacrum weakly depressed; pores far apart. Paired petals moderately depressed; anterior pair nearly twice as long as the posterior, diverging at an angle of approximately 90°; posterior pair diverging somewhat less; pores elongated-oval ; anterior poriferous zone of anterior pair much narrower near the apex; interporiferous zones narrow. Peristome at the anterior third, transversely oval, moderately lipped. Periproct large, transversely oval, at the top of the posterior truncation. Marginal fasciole descending below the periproct; hemipetalous fasciole meeting the marginal behind the anterior paired petals. Length of holotype 27 mm; width 24.5 mm; height 23.4 mm. Length of figured paratype 25.2 mm; width 24 mm; height 22 mm.
Occurrences
- Silicious molds of the interior, probably this species: Dawson-Albany Road 3.5 miles south of Sasser (S. W. McCallie).
- Road from Americus to Plains l.5 miles west of Muckalee Creek.
- Miller County, GA (Burt Carter 1987)
- Terrell County, GA (Burt Carter 1987)
- Sumter County, GA (Burt Carter 1987)
- Florida Museum of Natural History (FLMNH) holds
- Three specimens from Georgia
- 2 from Miller County (Burt Carter/ David Tilton)
- 1 from Dooly County (Burt Carter)
- Six specimens from Florida
- One specimen from Mississippi
- One specimen from Portugal
- Three specimens from Georgia
Geologic unit
- Early Oligocene: Suwannee limestone in Florida,
- Flint River formation in Georgia (Early Oligocene Residuum?)
- Miller County; Early Oligocene
- Late Oligocene, Terrell & Sumter Counties, GA, Chickasawhayan Stage. (Carter 1987)
Brissopatagus alabamensis
- Current nomenclature
- Formerly, Eupatagus alabamensis (Carter 1987)
- Cooke referred to species as Eupatagus (Brissopatagus) alabamensis (1959)
Brissopatagus alabamensis
Description
Test oval, slightly emarginate in front; upper surface rather low, highest in front of the apical system, geniculate in front. Apical system about the anterior third; four genital pores, close together; ethmolytic, the madreporite protruding far behind. Anterior ambulacrum narrow, moderately sunken. Petals in broad, shallow depressions; anterior pair very widely spreading, curved slightly forward; posterior pair longer, straight, diverging at an angle of 45°; pores oval, weakly conjugate; zones about equal in width. Peristome at the anterior quarter, reniform, three times as wide. as long, with a strongly protruding lip. Labium long and narrow, adjoining a rather short, V-shaped plastron. Ambulacra on lower side wide. Interambulacra reaching the peristome. Peripetalous fasciole narrow, slightly reentrant in interambulacra. Subanal fasciole wider, enclosing a heart-shaped escutcheon. A few very large tubercles confined within the peripetalous fasciole in paired interambulacra. Length of crushed holotype with margin broken 38 mm; width 38 mm; height 11 .mm.
Occurrence
Geologic unit
Description
Test oval, slightly emarginate in front; upper surface rather low, highest in front of the apical system, geniculate in front. Apical system about the anterior third; four genital pores, close together; ethmolytic, the madreporite protruding far behind. Anterior ambulacrum narrow, moderately sunken. Petals in broad, shallow depressions; anterior pair very widely spreading, curved slightly forward; posterior pair longer, straight, diverging at an angle of 45°; pores oval, weakly conjugate; zones about equal in width. Peristome at the anterior quarter, reniform, three times as wide. as long, with a strongly protruding lip. Labium long and narrow, adjoining a rather short, V-shaped plastron. Ambulacra on lower side wide. Interambulacra reaching the peristome. Peripetalous fasciole narrow, slightly reentrant in interambulacra. Subanal fasciole wider, enclosing a heart-shaped escutcheon. A few very large tubercles confined within the peripetalous fasciole in paired interambulacra. Length of crushed holotype with margin broken 38 mm; width 38 mm; height 11 .mm.
Occurrence
- Power plant on Kinchafoonee Creek north of Albany
- Flint River below the mouth of Cedar Creek, Crisp County.
- Dougherty County, GA (Carter 1987)
- Crisp County, GA (Carter 1987)
- Lee County, GA (Carter 1992)
- No Georgia specimens held by the FLMNH
- FMNH holds a single specimen from Alabama
Geologic unit
- Late Eocene
Brissopsis blanpiedi
- Current nomenclature
Brissopsis blanpiedi
Description
Test cordate, higher behind than in front; upper surface inflated; lower surface slightly convex, arched posteriorly. Apical system slightly in front of the center; four close-set genital pores; madreporite between and behind the posterior pair of pores; petals sunken,
slightly curved outward; anterior pair diverging at an angle of 85 °, extending about two-thirds the distance to the ambitus, a little longer than the posterior pair, which extend about halfway to the ambitus and diverge at an angle of 37°. Pores of paired petals large, oval, conjugate, those nearest the longitudinal axis obsolescent near the apical center; poriferous zones wider than the interporiferous zones. Anterior ambulacrum in a deep furrow, which deeply indents the margin but becomes obsolete near the peristome; pores small. Peristome large, oval, with a posterior lip; at the anterior fourth. Periproct large, round, at the top of a truncation, which slopes steeply backward, partly covered with plates. Length of figured specimen 33 mm; width 25.3 mm; height 16 mm.
Occurrence
Geologic Unit
Description
Test cordate, higher behind than in front; upper surface inflated; lower surface slightly convex, arched posteriorly. Apical system slightly in front of the center; four close-set genital pores; madreporite between and behind the posterior pair of pores; petals sunken,
slightly curved outward; anterior pair diverging at an angle of 85 °, extending about two-thirds the distance to the ambitus, a little longer than the posterior pair, which extend about halfway to the ambitus and diverge at an angle of 37°. Pores of paired petals large, oval, conjugate, those nearest the longitudinal axis obsolescent near the apical center; poriferous zones wider than the interporiferous zones. Anterior ambulacrum in a deep furrow, which deeply indents the margin but becomes obsolete near the peristome; pores small. Peristome large, oval, with a posterior lip; at the anterior fourth. Periproct large, round, at the top of a truncation, which slopes steeply backward, partly covered with plates. Length of figured specimen 33 mm; width 25.3 mm; height 16 mm.
Occurrence
- Cooke (1959) only listed one occurrence, in Mississippi.
- Ocmulgee Formation (reassigned from Cooper Marl, Pickering 1970, age possibly misidentified by Pickering)
- Pulaski County, GA (Burt Carter 1987)
- FLMNH holds
- Zero Georgia specimens
- Six specimens from Alabama
- One Specimen from Mississippi
Geologic Unit
- Middle Oligocene (Cooke 1959) at bottom of Glendon Limestone
- Latest Eocene (Pickering 1970)
- Early Oligocene, Vicksburgian Stage (Carter 1987)
Brissus bridgeboroensis
- Current nomenclature
- New Georgia species discovered and described by Burt Carter from the Bridgeboro Limestone of South Georgia.
Brissus bridgeboroensis
Description
A rounded, moderately inflated Brissus with long posterior paired petals compared with either anterior paired petals or test length. Petals nearly straight. Few pore-pairs per unit length in posterior paired petals. Apparently the subanal fasciole is more anteriorly located than in other Brissus species. Dimensions. Length, 36.5 mm (1.43”) Maximum width, 28.7 mm (1.13”). Maximum height, 21.0 mm (.826”) near posterior end. Height of apical system, 17.0 mm (.66”) Length of anterior paired petals, 10.2 mm (.40”)
Housed at the Smithsonian.
Not from Cooke’s paper but published by Burt Carter in the Journal of Paleontology, Sept. 1987,
Georgia Occurrence
Geologic Unit
Description
A rounded, moderately inflated Brissus with long posterior paired petals compared with either anterior paired petals or test length. Petals nearly straight. Few pore-pairs per unit length in posterior paired petals. Apparently the subanal fasciole is more anteriorly located than in other Brissus species. Dimensions. Length, 36.5 mm (1.43”) Maximum width, 28.7 mm (1.13”). Maximum height, 21.0 mm (.826”) near posterior end. Height of apical system, 17.0 mm (.66”) Length of anterior paired petals, 10.2 mm (.40”)
Housed at the Smithsonian.
Not from Cooke’s paper but published by Burt Carter in the Journal of Paleontology, Sept. 1987,
Georgia Occurrence
- Mitchell County, GA (Burt Carter discovered, described & published)
- Decatur County, GA, Climax Cave (Burt Carter)
- Additional finds in Alabama & Florida
- Florida Museum of Natural History (FLMNH) holds
- Three Georgia specimens
- Five Alabama specimens
- One Florida specimen
Geologic Unit
- Bridgeboro Limestone, Early Oligocene
Brochopleurus ptretiosus
- Current nomenclature
- Rare, Florida MNH only lists 2 specimens
Brochopleurus ptretiosus
Description
Horizontal outline circular; upper surface inflated, ambitus rounded, lower surface slightly concave around the peristome. Apical system dicyclic, with serrate outline, large; genital plates large, perforated near the outer ends of the prongs, bearing several small imperforate tubercles from which radiate vermiculate threads. Periproct nearly circular. Ambulacra regularly expanding to the ambitus; poriferous zones trigeminate, nearly straight above, in slightly inclined groups of three below, not at all expanded at the peristome. Interambulacra about twice as wide as ambulacra plates not much wider than high. Tubercles small, imperforate, arranged in vertical rows, one on each plate, with additional secondaries chiefly on the lower surface·; two rows on ambulacra adjacent to the poriferous zones and two on interambulacra passing through the center of the plates. Surface covered with elongated, confluent granules and threads, many of which radiate from the tubercles. Peristome rather small, circular, weakly notched.
Diameter of holotype 20 mm; height (crushed) 18.2 mm.
Occurrence
Geologic Unit
Remarks.
Mortensen's (1943) photographs of Progonechinus eocenicus (Duncan and Sladen) show a quite different type of decoration from that of this species, which seems very similar to Brochopleurus stellulatus (Duncan and Sladen).
Description
Horizontal outline circular; upper surface inflated, ambitus rounded, lower surface slightly concave around the peristome. Apical system dicyclic, with serrate outline, large; genital plates large, perforated near the outer ends of the prongs, bearing several small imperforate tubercles from which radiate vermiculate threads. Periproct nearly circular. Ambulacra regularly expanding to the ambitus; poriferous zones trigeminate, nearly straight above, in slightly inclined groups of three below, not at all expanded at the peristome. Interambulacra about twice as wide as ambulacra plates not much wider than high. Tubercles small, imperforate, arranged in vertical rows, one on each plate, with additional secondaries chiefly on the lower surface·; two rows on ambulacra adjacent to the poriferous zones and two on interambulacra passing through the center of the plates. Surface covered with elongated, confluent granules and threads, many of which radiate from the tubercles. Peristome rather small, circular, weakly notched.
Diameter of holotype 20 mm; height (crushed) 18.2 mm.
Occurrence
- No reported from Georgia (Cooke 1959)
- Lee County, GA (Carter 1987)
- FLMNH hold zero specimens
Geologic Unit
- Late Eocene
Remarks.
Mortensen's (1943) photographs of Progonechinus eocenicus (Duncan and Sladen) show a quite different type of decoration from that of this species, which seems very similar to Brochopleurus stellulatus (Duncan and Sladen).
Clypeaster cotteaui
- Current nomenclature
Clypeaster cotteaui
Description
The horizontal outline ovate, narrower in front; upper surface slightly arched; margin thick, broadly rounded; lower surface deeply concave. Apical system central. Petals extending three-fourths the way to the margin, slightly tumid; closed apically, wide open distally; inner rows of pores straight except near the apex, outer rows curved, rows nearly meeting at the tip, where there is a group of four pores. Peristome small, deeply sunken. Periproct near the margin. Tubercles large, deeply sunken in large scrobicules.
Length of figured specimen 64.4 mm, width 52.7 mm, height 20.0 mm.
Description
The horizontal outline ovate, narrower in front; upper surface slightly arched; margin thick, broadly rounded; lower surface deeply concave. Apical system central. Petals extending three-fourths the way to the margin, slightly tumid; closed apically, wide open distally; inner rows of pores straight except near the apex, outer rows curved, rows nearly meeting at the tip, where there is a group of four pores. Peristome small, deeply sunken. Periproct near the margin. Tubercles large, deeply sunken in large scrobicules.
Length of figured specimen 64.4 mm, width 52.7 mm, height 20.0 mm.
Occurrence
Geologic Unit
Remarks.
- Worth County on road from Isabella to Albany 6.4 miles west of Isabella and about 12 miles east of Albany
- Houston/Pulaski Counties, (Pickering 1970) Oligocene Residuum (Flint River Formation), very rare. (Pickering 1970)
- Pulaski County, GA (Carter 1987)
- Houston County, GA (Carter 1987)
- Mitchell County, GA (Carter 1987)
- Sumter County, GA (Carter 1987)
- FLMNH holds 48 specimens
- 1 from Italy
- 2 from Cuba
- 10 from Alabama
- 14 from Florida
- 21 from Georgia
Geologic Unit
- Late Oligocene, Suwannee limestone in Georgia
- Early Oligocene residuum
- Early Oligocene, Vicksburgian Stage (Carter 1987)
Remarks.
- The preceding description is based on the figured Cuban specimen which was identified and figured by Jackson. The only specimen from Georgia is rather defective, but the identification seems certain. The petals of Clypeaster cotteaui are similar to those of C. rogersi, but the margin is thicker, the lower concavity is much deeper, the tubercles are a little larger, and the periproct is nearer the margin.
Clypeaster rogersi
- Current nomenclature
Clypeaster rogersi
Description
Length ranging from less than 40 mm to 90 mm or more. Outline oval to sub-pentagonal; upper surface low to tumid apically; lower surface flattish, slightly concave near the peristome; margin usually thin. The apical system is central with five genital pores, tumid. Petals extending more than halfway to the margin, completely closed apically, wide open distally; poriferous zones somewhat narrower than the interporiferous, inner pores circular, outer pores slightly elongated, pores weakly conjugate; inner side of poriferous zones almost straight, outer side slightly convex. Peristome central, pentagonal, sides slightly swollen, like bourrelets. Ambulacral grooves straight, narrow, extending to the margin. Periproct circular, located about one-fifth the distance from the margin to the peristome. Tubercles on upper surface small, sunken; tubercles on lower surface larger, in much larger tubercules; intermediate spaces pitted.
Dimensions not noted.
Description
Length ranging from less than 40 mm to 90 mm or more. Outline oval to sub-pentagonal; upper surface low to tumid apically; lower surface flattish, slightly concave near the peristome; margin usually thin. The apical system is central with five genital pores, tumid. Petals extending more than halfway to the margin, completely closed apically, wide open distally; poriferous zones somewhat narrower than the interporiferous, inner pores circular, outer pores slightly elongated, pores weakly conjugate; inner side of poriferous zones almost straight, outer side slightly convex. Peristome central, pentagonal, sides slightly swollen, like bourrelets. Ambulacral grooves straight, narrow, extending to the margin. Periproct circular, located about one-fifth the distance from the margin to the peristome. Tubercles on upper surface small, sunken; tubercles on lower surface larger, in much larger tubercules; intermediate spaces pitted.
Dimensions not noted.
Occurrence
Geologic Unit
Remarks
Comparisons
Geologic unit
- Georgia: Old Jacksonboro, fork of Brier and Beaverdam Creeks, Screven County.
- Climax Cave, Decatur County, GA (Burt Carter)
- Lee County, GA (Burt Carter)
- Laurens County, GA (Burt Carter)
- Pulaski County (Pickering 1970), Mile Creek bed at Mile Branch Park boat ramp. 200 yards downstream from ramp, listed as abundant but little of the limestone is accessible with a boat.
- Bleckley County, GA; Red Dog Farm Road. (Thurman, Huddlestun & Michael Reagin, 2017)
- Pulaski County, GA (Carter 1987)
- Sumter County, GA (Carter 1987)
- FLMNH holds 237 specimens
- 6 from Georgia
- 133 from Alabama
- 52 From Florida
- 46 from Mississippi
Geologic Unit
- Middle and late Oligocene; (1959 dating) Vicksburg group in Mississippi and Alabama, Flint River formation in Georgia (the Flint River Formation is reassigned as residuum and is considered Early Oligocene).
- Marianna Limestone Formation, Early Oligocene (Reassigned from Pickering 1970, Byram Formation Unit B).
- Early Oligocene, Vicksburgian Stage (Carter 1987)
- Late Oligocene, Chickasawhayan Stage, Sumter County, GA. (Carter 1987)
Remarks
- The shape and size of Clypeaster rogersi is quite variable, but the shape of the petals is relatively constant. The species appears to be included in the section Orthanthus Mortensen. The specimens from the Suwannee limestone (USGS 14924), from the Flint River formation, and from the Meson formation tend to have slightly wider interporiferous zones than the typical form from the Marianna limestone, and their margin is thinner.
Comparisons
- Oligopygus haldemani is commonly smaller than O. wetherbyi, it is less elongated, and its periproct is much nearer the margin. O. colsoni Lambert is evidently a juvenile specimen of O. haldemani. Oligopygus rotundus has longer petals and the posterior slope of its oral depression is much steeper.
Geologic unit
- Late Eocene
Durhamella floridana
- Current nomenclature (Natural History Museum UK)
- Reassigned from Laganum floridanum
Durhamella floridana
Description
The specimens vary in length from 3.1 mm to 20 mm. The marginal outline is circular, to sub-pentagonal, with the anterior slightly pointed and the posterior blunted in some specimens. The test is wide, with little variation in the length-width ratio. The width averages 90 percent of the length in the smaller specimens (between 4 mm and 6 mm long) and 93 percent in the larger (over 13 mm long). The greatest width is central or slightly posterior of the center. The test is low, with the height approximately 29 percent
of the length in smaller specimens (6 mm long), 23 percent in specimens 10 mm long, and 17 percent in specimens over 17 mm long. The greatest height is at the apical system. The margin is thick, and the adapical surface is slightly depressed between the edge of the apical system to beyond the ends of the petals. The sutures are depressed along the adapical interambulacral plates between the petals and the ambulacral plates beyond the petals in a few of the specimens.The adoral surface is flat to very slightly depressed.
Description
The specimens vary in length from 3.1 mm to 20 mm. The marginal outline is circular, to sub-pentagonal, with the anterior slightly pointed and the posterior blunted in some specimens. The test is wide, with little variation in the length-width ratio. The width averages 90 percent of the length in the smaller specimens (between 4 mm and 6 mm long) and 93 percent in the larger (over 13 mm long). The greatest width is central or slightly posterior of the center. The test is low, with the height approximately 29 percent
of the length in smaller specimens (6 mm long), 23 percent in specimens 10 mm long, and 17 percent in specimens over 17 mm long. The greatest height is at the apical system. The margin is thick, and the adapical surface is slightly depressed between the edge of the apical system to beyond the ends of the petals. The sutures are depressed along the adapical interambulacral plates between the petals and the ambulacral plates beyond the petals in a few of the specimens.The adoral surface is flat to very slightly depressed.
Occurrence
Geologic Unit
- Glynn County, GA, from a 1,130 foot deep well core by the USGS near Brunswick.
- Echinoids occurred in strata identified my S.M. Herrick of the USGS as Middle Eocene Lake City Formation through foraminifera.
- 30 specimens of this species recovered.
- Houston County, GA (Carter 1987)
- Pulaski County, GA (Carter 1987)
- FLMNH holds 231 specimens
- Zero from Georgia
- 133 from Alabama
- 52 from Florida
- 46 from Mississippi
Geologic Unit
- Middle Eocene, Claibornian, Lake City Formation.
- Late Eocene, Jacksonian (Carter 1987)
Durhamella 0calana
- Current nomenclature
- Species does not occur in Cooke 1959
- Species reported described by Cooke in 1942
Durhamella 0calana
Description (The Echinoid Directory UK)
For the genus Durhamella is general, but images are of Durhamella ocalana.
Description (The Echinoid Directory UK)
For the genus Durhamella is general, but images are of Durhamella ocalana.
- Test oval in outline, flattened in profile with rounded margins.
- Internal supports concentric.
- 5 gonopores; apical disc subcentral. Hydropores open in a groove.
- Petals short, wide near apical disc and closed distally. Plating with demiplates.
- No food grooves.
- Ambulacral zones very much wider than interambulacral zones at ambitus.
- Basicoronal ambulacral and interambulacral plates of similar length. First paired post-basicoronal plates much larger than others.
- Periproct oral, towards posterior margin. Opening bounded by second and third pairs of interambulacral plates.
- Georgia, Pulaski County (Carter 1987)
- FLMNH holds
- Zero from Georgia
- 78 specimens from Florida
- Late Eocene, Jacksonian Stage (Carter 1987)
Echanthus georgiensis
- Current nomenclature.
- The Echinoid Directory, Natural History Museum, UK
- Also known as; Gitolampus georgiensis (Burt Carter 1987)
- The Echinoid Directory (UK) places Gitolampus georgiensis into Ecanthus georgiensis.
- Nomenclature possibly changed/challenged.
- (Neither genus nor species occurs in Florida Natural History Museum catalog)
Echanthus georgiensis
Description
Horizontal outline sub-pentagonal, slightly emarginate in front, sulcate behind, widest behind the midline; upper surface moderately inflated, highest point behind the apical system but in front of the center, slightly rostrate above the periproct; lower surface concave around the peristome; margin rounded. Apical system monobasal, four genital pores. Petals spatulate, open distally, extending more than halfway to the margin; poriferous zones of equal length, pores circular, obliquely conjugate;. interporiferous zones wider than the poriferous. Peristome anterior, beneath the apex, pentagonal, wider than long; phyllodes longer than wide; bourrelets inflated, granulated. Periproct terminal, vertical, higher than wide, in a vertical sulcus, above the margin. Upper surface and margin covered with small, crowded sunken tubercles; tubercles on lower surface larger; narrow sternal area without tubercles.
Occurrence
Geologic Unit
Remarks
Description
Horizontal outline sub-pentagonal, slightly emarginate in front, sulcate behind, widest behind the midline; upper surface moderately inflated, highest point behind the apical system but in front of the center, slightly rostrate above the periproct; lower surface concave around the peristome; margin rounded. Apical system monobasal, four genital pores. Petals spatulate, open distally, extending more than halfway to the margin; poriferous zones of equal length, pores circular, obliquely conjugate;. interporiferous zones wider than the poriferous. Peristome anterior, beneath the apex, pentagonal, wider than long; phyllodes longer than wide; bourrelets inflated, granulated. Periproct terminal, vertical, higher than wide, in a vertical sulcus, above the margin. Upper surface and margin covered with small, crowded sunken tubercles; tubercles on lower surface larger; narrow sternal area without tubercles.
Occurrence
- Dr. A. J. Parker's farm, Ellaville-Americus road 5 miles south of Ellaville. Type Specimen.
- Schley County, GA
- Randolph County, GA
- Florida Museum of Natural History (FLMNH) holds
- 1 from Alabama
Geologic Unit
- Paleocene, Clayton Formation
- Early-Mid Paleocene, Midwayan Stage (Carter 1987)
Remarks
- The type is a silicious pseudomorph damaged on the left side but otherwise well preserved. All the other specimens (from Alabama) are molds of the interior. The unique type of Cassidulus (Galerolampas) fontis has a transverse periproct, which has been distorted by crushing and which probably was vertical originally. It was found at a depth less than 1600 feet in a well drilled near Falling Water, 4 miles south of Chipley, Fla. The petals resemble those of Echanthus georgiensis.
Echinocyamus bisexus
- Current Nomenclature
- New species from the Brunswick, GA area described & published by Porter M. Kier in 1968. (Smithsonian)
- Sometime spelled as bisexis, but bisexus occurs in the original 1968 paper
- Recorded as Echinocyamus bisexis in the Florida Natural History Museum catalog.
Echinocyamus bisexus
Description
The specimens vary in length from 1.52 to 7.2 mm. The test is narrow, with the width averaging 67 percent of the length, although in the two smallest specimens, 2.9 and 1.52 mm long, the width is greater, 72 and 75 percent of the length respectively. The greatest width is posterior to the center. The anterior margin is pointed, the posterior more rounded. The test is low, with a height averaging 38 percent of the length and varying from 31 to 46 percent. The greatest height is posterior to the center, and the adapical surface is smoothly rounded, the adoral flattened.
11 females & 7 males recovered, they are unusual as they display sexual dimorphism.
Occurrence
Geologic Unit
Description
The specimens vary in length from 1.52 to 7.2 mm. The test is narrow, with the width averaging 67 percent of the length, although in the two smallest specimens, 2.9 and 1.52 mm long, the width is greater, 72 and 75 percent of the length respectively. The greatest width is posterior to the center. The anterior margin is pointed, the posterior more rounded. The test is low, with a height averaging 38 percent of the length and varying from 31 to 46 percent. The greatest height is posterior to the center, and the adapical surface is smoothly rounded, the adoral flattened.
11 females & 7 males recovered, they are unusual as they display sexual dimorphism.
Occurrence
- Glynn County, GA, from a 1,130 foot deep well core by the USGS near Brunswick.
- Echinoids occurred in strata identified my S.M. Herrick of the USGS as Middle Eocene Lake City Formation through foraminifera.
- Also known from Pender NC. (Burt Carter 1987)
- FLMNH holds no specimens
Geologic Unit
- Middle Eocene
Eupatagus antillarum
- Current nomenclature (Florida MNH)
- Also known as Eupatagus (Gymnopatagus) antillarum (Cooke 1959)
Eupatagus antillarum
Description
Horizontal outline obovate, truncated behind; upper surface moderately elevated, highest midway between the apical system and the periproct, sloping gently forward; lower surface flat; margin rounded. Apical system slightly eccentric forward, ethmolytic, the madreporite protruding far behind the ocular plates; four genital pores close together. Anterior ambulacrum narrow, not petaloid, slightly flattened, plates nearly equilateral. Petals long, extending nearly to the margin, slightly flexuous; anterior pair diverging at an angle of approximately 145°, posterior pair 40°; pores circular, strongly conjugate; poriferous zones nearly closed, narrow. Peristome at the anterior third, rounded, somewhat wider than long; labrum not conspicuously projecting. Floscelle conspicuous. All interambulacra reaching the peristome. Periproct terminal vertical, higher than wide, about mid-height, at the top of a small truncation. Peripetalous fasciole not indented; subanal fasciole heart shaped. Large tubercles arranged in parallel zigzag rows in the four lateral interambulacra, confined within the peripetalous fasciole. Smaller tubercles closely cover the interambulacra on the lower side. Tubercles arranged in radiating rows on the escutcheon, forming a pattern suggestive of a pair of spread wings. Lower parts of ambulacra smooth and appearing calloused. Length of figured specimens 58.5 and 42.3 mm; width 50.3 and 35.5 ; height 29 and 18.5 mm.
Occurrence
Description
Horizontal outline obovate, truncated behind; upper surface moderately elevated, highest midway between the apical system and the periproct, sloping gently forward; lower surface flat; margin rounded. Apical system slightly eccentric forward, ethmolytic, the madreporite protruding far behind the ocular plates; four genital pores close together. Anterior ambulacrum narrow, not petaloid, slightly flattened, plates nearly equilateral. Petals long, extending nearly to the margin, slightly flexuous; anterior pair diverging at an angle of approximately 145°, posterior pair 40°; pores circular, strongly conjugate; poriferous zones nearly closed, narrow. Peristome at the anterior third, rounded, somewhat wider than long; labrum not conspicuously projecting. Floscelle conspicuous. All interambulacra reaching the peristome. Periproct terminal vertical, higher than wide, about mid-height, at the top of a small truncation. Peripetalous fasciole not indented; subanal fasciole heart shaped. Large tubercles arranged in parallel zigzag rows in the four lateral interambulacra, confined within the peripetalous fasciole. Smaller tubercles closely cover the interambulacra on the lower side. Tubercles arranged in radiating rows on the escutcheon, forming a pattern suggestive of a pair of spread wings. Lower parts of ambulacra smooth and appearing calloused. Length of figured specimens 58.5 and 42.3 mm; width 50.3 and 35.5 ; height 29 and 18.5 mm.
Occurrence
- Jamaica, Florida & Alabama (Cooke 1959)
- Houston County, GA (Carter 1992)
- Florida Museum of Natural History (FLMNH) holds 786 specimens.
- Zero from Georgia
- 786 From Florida
- Early part of late Eocene (Cooke 1959)
Eupatagus ocalanus
- Current Nomenclature
Eupatagus ocalanus
Description
Horizontal outline subovate, truncated behind; upper surface moderately inflated, median line horizontal behind the apex, rostrate behind, rather steeply sloping in front; lower surface nearly flat; margin broadly rounded. Apical system slightly anterior; small; four genital pores close together; ethmolytic, the madreporite extending behind the ocular plates. Anterior ambulacrum flattened, narrow, the plates nearly equilateral, pore pairs small, longitudinal. Petals slightly sunken, flexuous, extending about two-thirds the way to the margin, the posterior pair the longer; anterior pair diverging at an angle of 145 °, the posterior about 40°, pores oval, strongly conjugate; anterior poriferous zone of anterior petals diminishing in width near the apical system. Peristome large, oval, at the anterior third; labrum not conspicuous. Periproct large, oval, vertical, higher than wide; at the top of a vertical truncation; barely visible from above. Peripetalous fasciole oval, narrow, subanal fasciole heart shaped, enclosing an escutcheon. Large tubercles confined within the peri-petalous fasciole, arranged linearly in paired interambulacra; somewhat smaller and scattered on posterior inter-ambulacrum.
Length of type 68.5 mm; width 58 mm; height 27 mm.
Occurrence
Description
Horizontal outline subovate, truncated behind; upper surface moderately inflated, median line horizontal behind the apex, rostrate behind, rather steeply sloping in front; lower surface nearly flat; margin broadly rounded. Apical system slightly anterior; small; four genital pores close together; ethmolytic, the madreporite extending behind the ocular plates. Anterior ambulacrum flattened, narrow, the plates nearly equilateral, pore pairs small, longitudinal. Petals slightly sunken, flexuous, extending about two-thirds the way to the margin, the posterior pair the longer; anterior pair diverging at an angle of 145 °, the posterior about 40°, pores oval, strongly conjugate; anterior poriferous zone of anterior petals diminishing in width near the apical system. Peristome large, oval, at the anterior third; labrum not conspicuous. Periproct large, oval, vertical, higher than wide; at the top of a vertical truncation; barely visible from above. Peripetalous fasciole oval, narrow, subanal fasciole heart shaped, enclosing an escutcheon. Large tubercles confined within the peri-petalous fasciole, arranged linearly in paired interambulacra; somewhat smaller and scattered on posterior inter-ambulacrum.
Length of type 68.5 mm; width 58 mm; height 27 mm.
Occurrence
- Bainbridge
- Decatur, County (Carter 1987)
- Lee County, GA (Carter 1987)
- FLMNH holds 32 specimens.
- 6 from Georgia
- 2 from Houston County (Burt Carter)
- 3 from Lee County (Burt Carter)
- 1 from Crisp County
- 19 from Florida
- 6 from Alabama
- 1 with unlisted location
- 6 from Georgia
- Late Eocene, Jacksonian Stage (Carter 1987)
- Eupatagus ocalanus is more delicate than E. antillarum and the plates in the upper parts of its paired interambulacra are less swollen. Its apical system is farther forward, and the slope to the anterior edge is more abrupt. Its upper surface. resembles that of Plagiobrissus grandis, but its anterior petals are more widely spreading, its posterior ambulacra are much wid.tr underneath, and their outer edges are not parallel but diverge backward. Moreover, it appears to lack an anal fasciole although there is some indication of an incipient one.
Eurhodia patelliformis
- Current nomenclature
Eurhodia patelliformis
Description
Test elongated; horizontal outline semicircular in front, narrowly truncated behind, broadly truncated on posterolateral margins; upper surface evenly arched; lower surface flat; margin subacute. Apical system slightly anterior, directly above the periproct, monobasal, four genital pores. Petals lanceolate, closed at the apex, open distally, the anterior pair somewhat shorter than the others; poriferous zones of nearly equal length, somewhat narrower than the interporiferous; inner pores circular, outer pores oval or elongate. Peristome pentagonal, slightly longer than wide; bourrelets strong, bulbous; details of phyllodes obscure. Periproct supramarginal, nearly circular, opening into a shallow sulcus, which indents the margin and continues forward into the periproct, forming an internal shelf or tube. Upper surface and margin covered with small sunken tubercles; tubercles on lower surface much larger, sunken in deep pits; posterior inter-ambulacrum on lower surface without tubercles but deeply pitted; similar pits surround the anterior phyllode. Length of specimen 25.3 mm; width 17.8 mm; height 10 mm.
Occurrences
Description
Test elongated; horizontal outline semicircular in front, narrowly truncated behind, broadly truncated on posterolateral margins; upper surface evenly arched; lower surface flat; margin subacute. Apical system slightly anterior, directly above the periproct, monobasal, four genital pores. Petals lanceolate, closed at the apex, open distally, the anterior pair somewhat shorter than the others; poriferous zones of nearly equal length, somewhat narrower than the interporiferous; inner pores circular, outer pores oval or elongate. Peristome pentagonal, slightly longer than wide; bourrelets strong, bulbous; details of phyllodes obscure. Periproct supramarginal, nearly circular, opening into a shallow sulcus, which indents the margin and continues forward into the periproct, forming an internal shelf or tube. Upper surface and margin covered with small sunken tubercles; tubercles on lower surface much larger, sunken in deep pits; posterior inter-ambulacrum on lower surface without tubercles but deeply pitted; similar pits surround the anterior phyllode. Length of specimen 25.3 mm; width 17.8 mm; height 10 mm.
Occurrences
- Baker County (Carter 1987)
- Power plant 2 miles north of Albany.
- Power plant at mouth of Kinchafoone Creek, 3.3. miles north of Albany.
- Huguenen Ferry, Flint River, mouth of Gum Creek, Crisp County.
- Dougherty County, GA (Carter 1987)
- Crisp County, GA (Carter 1987)
- Lee County, GA (Carter 1987)
- Florida Museum of Natural History (FLMNH) holds 38 specimens
- 18 from Georgia
- 11 from Dougherty County
- 4 from Lee County
- 18 from Florida
- 2 from Alabama
- 18 from Georgia
- Late Eocene, Jacksonian Stage (Carter 1987)
- Eurhodia patelliformis is smaller than E. rugosa, and its periproct is more nearly circular. The posterior truncation is narrower, and the posterolateral sides are straighter.
Eurhodia rugosa
- Current nomenclature
Eurhodia rugosa
Description
Test large; horizontal outline elliptical, nearly 1.5 times as long as wide; upper surface evenly arched, somewhat rostrate above the periproct; oval surface; slightly concave, margin acutely rounded. Apical system in front of the center, directly above the peristome; monobasal, with four genital perforations. Ambulacra petaloid; petals lanceolate, closed at the apex, open distally; pores oval, the outer ones somewhat longer than the inner; all poriferous and interporiferous zones about equal in width. Peristome pentagonal, longer; than wide; floscelle star shaped; phyllodes having a pair of conspicuous pits or pores at the inner end and several irregularly distributed pores or pits distally bourrelets tumid, granulated. Periproct supramarginal, well back from the margin, transversely elongated, opening into a shallow depression, which extends backward to the margin arid forward about-2 mm into; the periproct, forming a shelf beneath it. Entire upper surface and margin closely covered with small depressed tubercles; oral side decorated with large, deeply depressed tubercles in the lateral interambulacra, and deep pits in the posterior inter-ambulacra and anterior ambulacrum, the intermediate spaces in these areas covered with very small tubercles. Length of figured specimen 35 mm; width 25 mm; height 13.6 mm. A larger specimen measures 51 by 36 by 18mm.
Occurrence
Description
Test large; horizontal outline elliptical, nearly 1.5 times as long as wide; upper surface evenly arched, somewhat rostrate above the periproct; oval surface; slightly concave, margin acutely rounded. Apical system in front of the center, directly above the peristome; monobasal, with four genital perforations. Ambulacra petaloid; petals lanceolate, closed at the apex, open distally; pores oval, the outer ones somewhat longer than the inner; all poriferous and interporiferous zones about equal in width. Peristome pentagonal, longer; than wide; floscelle star shaped; phyllodes having a pair of conspicuous pits or pores at the inner end and several irregularly distributed pores or pits distally bourrelets tumid, granulated. Periproct supramarginal, well back from the margin, transversely elongated, opening into a shallow depression, which extends backward to the margin arid forward about-2 mm into; the periproct, forming a shelf beneath it. Entire upper surface and margin closely covered with small depressed tubercles; oral side decorated with large, deeply depressed tubercles in the lateral interambulacra, and deep pits in the posterior inter-ambulacra and anterior ambulacrum, the intermediate spaces in these areas covered with very small tubercles. Length of figured specimen 35 mm; width 25 mm; height 13.6 mm. A larger specimen measures 51 by 36 by 18mm.
Occurrence
- South Carolina & North Carolina (Cooke 1959)
- No Georgia reports recorded by Cooke.
- Houston County, GA (Carter 1992)
- Crisp County, GA, Lake Blackshear
- FLMNH Holds 25 specimens
- 3 from Georgia (Burt Carter)
- 1 from Houston County
- 2 from Crisp County
- 18 from North Carolina
- 4 from South Carolina
- 3 from Georgia (Burt Carter)
- Middle Eocene, Santee Limestone (Cooke 1959)
Fibularia alabamaensis
- Current nomenclature (NMNH Smithsonian)
- Unreported in Georgia by Cooke (1959)
- Reported in 1968 by Porter M. Kier
Fibularia alabamaensis
Description
Test ovoid. Apical system central, with four genital pores rather far apart, apparently having large ocular plates, the posterior pair in contact. Petals extending more than halfway to the margin; plates simple, crooked, increasing in width distally; pore pairs oblique, pores conjugate. Peristome central, small, circular, slightly depressed. Periproct smaller, circular, nearer the peristome than the margin. Tubercles sunken, close together. Length of type 7.4 mm; width 5.9 mm; height 5.4 mm.
Description
Test ovoid. Apical system central, with four genital pores rather far apart, apparently having large ocular plates, the posterior pair in contact. Petals extending more than halfway to the margin; plates simple, crooked, increasing in width distally; pore pairs oblique, pores conjugate. Peristome central, small, circular, slightly depressed. Periproct smaller, circular, nearer the peristome than the margin. Tubercles sunken, close together. Length of type 7.4 mm; width 5.9 mm; height 5.4 mm.
Occurrence
Geologic Unit
- Alabama (Cooke 1959)
- Glynn County, GA, from a 1130 ft well core by the USGS near Brunswick. (Kier 1968)
- Echinoids occurred in strata identified my S.M. Herrick of the USGS as Middle Eocene Lake City Formation through foraminifera.
- Florida Museum of Natural History does not list
Geologic Unit
- Alabama; Late Eocene, (Cooke 1959)
- Georgia; Claibornian, Middle Eocene (Kier 1968)
Fibularia vaughani
- Current Nomenclature.
- Also spelled as Fibularia vaughni (Carter 1987)
Fibularia vaughani
Description
Test elongated, smaller in front than behind, inflated above -and below, depressed around the peristome. Apical system central, with four genital pores wide apart. Petals extending about halfway to the margin; poriferous zones straight, slightly diverging, open at the outer ends; interporiferous zones slightly wider than the poriferous. Peristome circular, large, slightly sunken, central. Periproct small, circular, nearer the peristome than the margin. Tubercles close-set, sunken. Length of type 7.3 mm, width 5.2 mm, height 4.2mm
Occurrence
Geologic unit
Description
Test elongated, smaller in front than behind, inflated above -and below, depressed around the peristome. Apical system central, with four genital pores wide apart. Petals extending about halfway to the margin; poriferous zones straight, slightly diverging, open at the outer ends; interporiferous zones slightly wider than the poriferous. Peristome circular, large, slightly sunken, central. Periproct small, circular, nearer the peristome than the margin. Tubercles close-set, sunken. Length of type 7.3 mm, width 5.2 mm, height 4.2mm
Occurrence
- Georgia; Little Horseshoe Bend on the Flint River 4 miles below Bainbridge.
- No additional GA reports, very well-known from Florida
- Decatur County, GA (Carter 1987)
- Dougherty, County, GA (Carter 1992)
- FLMNH holds 127 specimens
- All from Florida
Geologic unit
- Late Eocene, Jacksonian Stage (Carter 1987)
Gagaria mossomi
- Current Nomenclature
- Unreported in Georgia by Cooke in 1959
Gagaria mossomi
Description
Test sub-hemispherical; horizontal outline circular or sub-pentagonal. Apical system pentagonal; madreporite swollen; ocular I barely reaching the periproct, other oculars exsert. Periproct large, nearly circular, central. Ambulacra about half as wide as interambulacra; poriferous zones uniserial, straight, trigeminate; plates composed of a narrow upper member with one zygopore and a wide compound member with two zygopores. Two vertical rows of large crenate imperforate primary tubercles in each area. Smaller tubercles and granules abundant on and below the ambitus. Peristome medium sized; moderately notched.
Height of larger co-type, a fragment, 20 mm; horizontal diameter of smaller co-type 15 mm; height 14.5 mm; diameter of peristome 6 mm.
Occurrence
Geologic unit
Remarks
Description
Test sub-hemispherical; horizontal outline circular or sub-pentagonal. Apical system pentagonal; madreporite swollen; ocular I barely reaching the periproct, other oculars exsert. Periproct large, nearly circular, central. Ambulacra about half as wide as interambulacra; poriferous zones uniserial, straight, trigeminate; plates composed of a narrow upper member with one zygopore and a wide compound member with two zygopores. Two vertical rows of large crenate imperforate primary tubercles in each area. Smaller tubercles and granules abundant on and below the ambitus. Peristome medium sized; moderately notched.
Height of larger co-type, a fragment, 20 mm; horizontal diameter of smaller co-type 15 mm; height 14.5 mm; diameter of peristome 6 mm.
Occurrence
- Unreported in Georgia until 1970, reported by Sam Pickering (Bulletin 81) as rare in the Early Oligocene residuum (reassigned from Flint River Formation) within the Perry, Cochran, Hawkinsville areas
- Pickering’s (1970) remains the only Georgia report.
- Florida Museum of Natural History reports many specimens from Florida & North Carolina
- Pulaski County, GA (Carter 1987)
- Florida Museum of Natural History holds 76 specimens
- Zero from Georgia
- 38 From Florida
- 38 from North Carolina
Geologic unit
- Early Oligocene
- Late Oligocene, Chickasawhayan Stage (Carter 1987)
Remarks
- This species seems to be common at the type locality but is not usually well preserved. Only one individual retains the apical system. The madreporite is inflated and ocular I penetrates to the periproct. Some individuals have a sub-pentagonal outline, in this respect resembling Gagaria venustula (Duncan and Sladen), the type species.
Gauthieria speciosa
- Cooke acknowledges species (1959)
Gauthieria speciosa
Description
Small, circular, relatively flat, very slight invagination of oral surface. Apical disk large, pronged posteriorly, details of apical disc unknown. Ambulacra about half as wide as interambulacra, pore pairs linear for most part, a little arcuate above the ambitus; quadrigeminate, phymosomatoid compounding, becoming trigeminate near apical disc. Peristome about a third of test diameter, circular, weakly notched. Primary tubercles imperforate, crenulate.
Occurrence.
Geologic Unit
Remarks
Description
Small, circular, relatively flat, very slight invagination of oral surface. Apical disk large, pronged posteriorly, details of apical disc unknown. Ambulacra about half as wide as interambulacra, pore pairs linear for most part, a little arcuate above the ambitus; quadrigeminate, phymosomatoid compounding, becoming trigeminate near apical disc. Peristome about a third of test diameter, circular, weakly notched. Primary tubercles imperforate, crenulate.
Occurrence.
- New Jersey (Zachos 2017)
- Georgia; Clayton Formation, banks of Chattahoochee River below Ft. Gaines Dam, Ft. Gaines, Clay County, Georgia
Geologic Unit
- Early Paleocene, Danian Stage, Clayton Formation (Zachos 2017)
Remarks
- Description is based on the original published description. The Georgia specimen differs from the New Jersey material in the size of secondary tubercles, which are larger in the Vincentown specimens.
Gitolampas georgiensis
- Current nomenclature (Florida MNH)
Gitolampas georgiensis
Description
Medium size, outline sub-pentagonal, often somewhat protruding posteriorly, low to slightly inflated, lower surface concave around peristome, margin rounded. Apical disc monobasal, four genital pores opening into the proximal ends of the paired interambulacra; ocular plates small but distinct. Petals long and narrow, anterior pair diverge at 140º, posterior pair diverge at 60º. Petals extend nearly to margin, open distally; pores circular to elliptical, conjugate, oblique in midsection; interporiferous zones up to twice as wide as poriferous zones; pores single beyond petals, one pore per ambulacral plate orally, restricted to adradiad sutures except in floscelle. Peristome anterior, pentagonal, nearly equant; phyllodes well developed, one, sometimes two sphaeridial pits, bourrelets slightly inflated. Periproct marginal, enclosed between 5th pair of post-basicoronal plates below the ambitus and the 6th pair above vertical, taller than wide, indents posterior margin. Aboral and marginal surface covered in small, sunken tubercles interspersed with fine granules; tubercles larger on oral surface, increasing in size and decreasing in density towards peristome, but denser and smaller within area of the floscelle, fading into granules on the bourrelets; narrow, naked sternal area.
Occurrence
Description
Medium size, outline sub-pentagonal, often somewhat protruding posteriorly, low to slightly inflated, lower surface concave around peristome, margin rounded. Apical disc monobasal, four genital pores opening into the proximal ends of the paired interambulacra; ocular plates small but distinct. Petals long and narrow, anterior pair diverge at 140º, posterior pair diverge at 60º. Petals extend nearly to margin, open distally; pores circular to elliptical, conjugate, oblique in midsection; interporiferous zones up to twice as wide as poriferous zones; pores single beyond petals, one pore per ambulacral plate orally, restricted to adradiad sutures except in floscelle. Peristome anterior, pentagonal, nearly equant; phyllodes well developed, one, sometimes two sphaeridial pits, bourrelets slightly inflated. Periproct marginal, enclosed between 5th pair of post-basicoronal plates below the ambitus and the 6th pair above vertical, taller than wide, indents posterior margin. Aboral and marginal surface covered in small, sunken tubercles interspersed with fine granules; tubercles larger on oral surface, increasing in size and decreasing in density towards peristome, but denser and smaller within area of the floscelle, fading into granules on the bourrelets; narrow, naked sternal area.
Occurrence
- Georgia; Clayton Formation, Dr. A.J. Parkes farm, 5 miles south of Ellaville, Schley County.
- Alabama
- FLMNH holds 11 specimens
- 5 from Georgia (Burt Carter)
- 3 from Randolph County
- 2 from Clay County
- 6 from Alabama
- 5 from Georgia (Burt Carter)
- Early Paleocene, Danian Stage, Clayton Formation (McBryde Member)
Laganum floridanum
- Genus does not appear in the catalog of the Florida Natural History Museum
- Genus does not appear in the Echinoid Directory (UK)
- Genus does occur in the EOL (Encyclopedia of Life) by National Museum of Natural History (Smithsonian)
Laganum floridanum
Description
Horizontal outline oval; upper surface tumid in the apical region, depressed in the sub-margin; margin thick, rounded; lower surface very slightly concave. Apical system having five genital pores far apart. Petals lanceolate, broad; poriferous zones curved inward at each end, wide open at the apical end, nearly closed distally. Peristome small, central. No ambulacral furrows. Periproct small, circular, about one-fourth the way from the margin to the peristome. Tubercles sunken.
Length 19.6 mm; width 17.7 mm; height 4.2 mm.
Occurrence
The petals of Laganum floridanum resemble those of L. laganum but are proportionately shorter. The poriferous zones are closer together at the apical ends than those of L. ocalanum Cooke. The periproct is farther back than in L. laganum, and ambulacral furrows are wanting. The species is represented by the type and two other specimens from the same locality.
Description
Horizontal outline oval; upper surface tumid in the apical region, depressed in the sub-margin; margin thick, rounded; lower surface very slightly concave. Apical system having five genital pores far apart. Petals lanceolate, broad; poriferous zones curved inward at each end, wide open at the apical end, nearly closed distally. Peristome small, central. No ambulacral furrows. Periproct small, circular, about one-fourth the way from the margin to the peristome. Tubercles sunken.
Length 19.6 mm; width 17.7 mm; height 4.2 mm.
Occurrence
- Florida, Levy County
- Georgia, Tivola Limestone, common (Pickering 1970)
- Author (Thurman) doubts ranking as common in the Tivola, suspects it might be rare.
- Late Eocene
The petals of Laganum floridanum resemble those of L. laganum but are proportionately shorter. The poriferous zones are closer together at the apical ends than those of L. ocalanum Cooke. The periproct is farther back than in L. laganum, and ambulacral furrows are wanting. The species is represented by the type and two other specimens from the same locality.
Lytechinus floralanus
- Current nomenclature
Lytechinus floralanus
Description (as written)
Test small, circular, depressed. Apical system unknown. Ambulacra nearly three-quarters as wide as the interambulacra; zygopores in arcs of three to each compound plate, aligned in oblique groups of three; compound plates about twice as wide as high. Tubercles imperforate, smooth; primary tubercles in the center of each plate, two vertical rows in each area; secondary tubercles nearly as large, in vertical rows. Granules encircling the primary tubercles and filling he intermediate spaces, leaving no bare areas. Peristome large; notches as deep as wide. Horizontal diameter 22.5 mm; height 11 mm; diameter of peristome about 11 mm.
Occurrence
Description (as written)
Test small, circular, depressed. Apical system unknown. Ambulacra nearly three-quarters as wide as the interambulacra; zygopores in arcs of three to each compound plate, aligned in oblique groups of three; compound plates about twice as wide as high. Tubercles imperforate, smooth; primary tubercles in the center of each plate, two vertical rows in each area; secondary tubercles nearly as large, in vertical rows. Granules encircling the primary tubercles and filling he intermediate spaces, leaving no bare areas. Peristome large; notches as deep as wide. Horizontal diameter 22.5 mm; height 11 mm; diameter of peristome about 11 mm.
Occurrence
- Georgia, Bainbridge
- Decatur County, GA (Carter 1987)
- Florida Museum of Natural History (FLMNH) holds 10 specimens
- All from Alabama
- Late Eocene, Jacksonian Stage (Carter 1987)
- This species is represented by only the two imperfect types. Their gill slits, which are not well preserved, are much deeper and sharper than those of Psammechinus but seem to be shallower and proportionately wider than those of Lytechinus variegatus. Their coronal plates are less elongated than those of L. variegatus probably because of their smaller size-and the entire surface is covered with tubercles or granules. The arrangement of the pores is similar to that of Oligophyma cellense, but the secondary tubercles seem to be larger and more numerous than in that species.
Laganum ocalanum
- Current nomenclature
- Florida Museum of Natural History only catalogs a single specimen from Florida
Laganum ocalanum
Description
Horizontal outline sub-oval; upper surface tumid in the apical region, depressed in the sub-margin; margin thick, rounded; lower surface flat. Apical system having five genital pores rather far apart between the inner ends of the poriferous zones; hydropores apparently in very fine, short, inconspicuous grooves. Petals short, extending halfway to the margin, spade-shaped; poriferous zones nearly closed at the distal end, wide open at
the apical end. Plates of sub-margin conspicuously tumid. Peristome pentagonal, central. Periproct small, circular, one-third or less the way from the margin to the peristome. Ambulacra on lower surface punctate, without grooves. Tubercles small, depressed; thickly scattered on upper surface, farther apart on lower. Length of holotype 22.3 mm; width 19.5 mm; height 3.0.mm.
Occurrence
Description
Horizontal outline sub-oval; upper surface tumid in the apical region, depressed in the sub-margin; margin thick, rounded; lower surface flat. Apical system having five genital pores rather far apart between the inner ends of the poriferous zones; hydropores apparently in very fine, short, inconspicuous grooves. Petals short, extending halfway to the margin, spade-shaped; poriferous zones nearly closed at the distal end, wide open at
the apical end. Plates of sub-margin conspicuously tumid. Peristome pentagonal, central. Periproct small, circular, one-third or less the way from the margin to the peristome. Ambulacra on lower surface punctate, without grooves. Tubercles small, depressed; thickly scattered on upper surface, farther apart on lower. Length of holotype 22.3 mm; width 19.5 mm; height 3.0.mm.
Occurrence
- Over a dozen Florida locations are given
- Houston County, GA; listed as “common” in the Tivola Limestone (Pickering 1970)
- Authur (Thurman) would rate as “rare” but present in the Tivola Limestone of Houston County.
- FLMNH holds a single specimen from Florida
- Late Eocene
- This species differs from Laganum floridanum in the tumid plates of the submarginal area and in the greater dista1ce between the poriferous zones at the apical end of the petals.
Leniechinus herricki
- Current nomenclature
- New species from the Brunswick, GA area described & published by Porter M. Kier in 1968. (Smithsonian)
Leniechinus herricki
Description
The specimens vary in length from 3.9 to 21.0 mm. The test is narrow, the width from 60 to 70 percent of the length, with the greatest width posterior to the center. The anterior margin is pointed, the posterior blunted. The test is low, with a height varying from 20 to 23 percent of the length. The greatest height is central at the apical system. The margin is
thin, and the adoral surface flat to slightly depressed.
Occurrence
Description
The specimens vary in length from 3.9 to 21.0 mm. The test is narrow, the width from 60 to 70 percent of the length, with the greatest width posterior to the center. The anterior margin is pointed, the posterior blunted. The test is low, with a height varying from 20 to 23 percent of the length. The greatest height is central at the apical system. The margin is
thin, and the adoral surface flat to slightly depressed.
Occurrence
- Glynn County, GA, from a 1,130 foot deep well core by the USGS near Brunswick.
- Echinoids occurred in strata identified my S.M. Herrick of the USGS as Middle Eocene Lake City Formation through foraminifera.
- Claibornian, Middle Eocene, Lake City Formation.
Linthia prima
- Current nomenclature
- New species by Cooke (1942).
- Confirmed by Carter (1987)
- Another specimen recovered & identified by Zachos (2017)
- Eupatagus? (Brissopatagus?) primus Cooke, 1942
Linthia prima
Description
Test cordate; upper surface high, highest point in front of the apical system; anterior margin deeply cut by a rounded sulcus, which slopes steeply from a point in front of the apical system to the peristome. Apical system nearly central, with four genital pores. Petals in broad depressions; anterior pair longer than the posterior, extending nearly to the margin, straight, widely diverging, nearly closed; pores round, conjugate; zones equally wide distally, but interporiferous zones and front poriferous zones narrowing more rapidly than the back poriferous zone near the apical system. Posterior petals straight, extending about two-thirds the way to the margin; outer poriferous zones longer than the inner. Pore pairs of the anterior ambulacral area oblique, narrow, crossing the tumid part of the test and becoming much wider apart and replaced by single pores alternating in position in the sulcus. Posterior interambulacral area arched, apparently covered with tubercles and granules. Peristome: far forward. Length (broken) 34.5 mm; width 35 mm; height about 24mm.
Description
Test cordate; upper surface high, highest point in front of the apical system; anterior margin deeply cut by a rounded sulcus, which slopes steeply from a point in front of the apical system to the peristome. Apical system nearly central, with four genital pores. Petals in broad depressions; anterior pair longer than the posterior, extending nearly to the margin, straight, widely diverging, nearly closed; pores round, conjugate; zones equally wide distally, but interporiferous zones and front poriferous zones narrowing more rapidly than the back poriferous zone near the apical system. Posterior petals straight, extending about two-thirds the way to the margin; outer poriferous zones longer than the inner. Pore pairs of the anterior ambulacral area oblique, narrow, crossing the tumid part of the test and becoming much wider apart and replaced by single pores alternating in position in the sulcus. Posterior interambulacral area arched, apparently covered with tubercles and granules. Peristome: far forward. Length (broken) 34.5 mm; width 35 mm; height about 24mm.
Occurrence:
- Dr. A. J. Parke's farm on the Americus road 5 miles south of Ellaville, Schley County (S. W. McCallie).
- Schley County, GA; Midwayan Stage, Early to Mid Paleocene (Carter 1987)
- Schley County, GA (Zachos 2017)
- Paleocene, Clayton Formation
- This species is represented by only one mold of the interior, to which a few fragments of the silicified test are clinging; It was associated with Echanthus georgiensis (Twitchell). The proper generic affiliation cannot be determined until better specimens are obtained. The long, straight petals suggest Linthia.
Macropneustes mortoni
- Current nomenclature
- Also see spelled as Macropnuestes mortoni
Macropneustes mortoni
Description (as written)
Test thin. Horizontal outline broadly oval, flattened or very slightly emarginate in front. Upper surface swollen, evenly rounded. Margin broadly rounded. Lower surface flattish, depressed around the peristome. Apical system at the anterior third; 4 genital pores, close together; ethmolytic, the madreporite extending far behind the ocular plates. Anterior ambulacrum not petaloid, slightly depressed, plainly depressed near the peristome. Petals flush or slightly depressed, straight, long, extending nearly to the margin, open distally; inner pores circular, outer pores oval, pores conjugate; interporiferous zones equal in width to the poriferous zones, not expanding medially. Peristome lunate, with a prominent posterior lip; at the anterior third. Periproct large, broadly oval, erect, higher than wide, about mid-height, at the top of a slight depression. Peripetalous fasciole narrow, circular in front, straight or offset behind, zigzag on the sides. Subanal fasciole broadly U-shaped. Large tubercles crenulate, perforated, not confined within the fascioles. 78mm length for figured specimen# USGS 7121.
Description (as written)
Test thin. Horizontal outline broadly oval, flattened or very slightly emarginate in front. Upper surface swollen, evenly rounded. Margin broadly rounded. Lower surface flattish, depressed around the peristome. Apical system at the anterior third; 4 genital pores, close together; ethmolytic, the madreporite extending far behind the ocular plates. Anterior ambulacrum not petaloid, slightly depressed, plainly depressed near the peristome. Petals flush or slightly depressed, straight, long, extending nearly to the margin, open distally; inner pores circular, outer pores oval, pores conjugate; interporiferous zones equal in width to the poriferous zones, not expanding medially. Peristome lunate, with a prominent posterior lip; at the anterior third. Periproct large, broadly oval, erect, higher than wide, about mid-height, at the top of a slight depression. Peripetalous fasciole narrow, circular in front, straight or offset behind, zigzag on the sides. Subanal fasciole broadly U-shaped. Large tubercles crenulate, perforated, not confined within the fascioles. 78mm length for figured specimen# USGS 7121.
Georgia Occurrences:
- Palmyra, Lee County.
- Powerplant on Kinchafoonee Creek north of Albany.
- Just above bridge of Albany Northern Railway over Muckafoonee Creek near Albany.
- East side Flint River at powerplant above Albany.
- East bank of Flint River at mouth of creek in the northeastern corner of Dougherty County.
- Clinchfield Formation, very rare (Pickering 1970)
- Tivola Limestone, rare (Pickering 1970)
- Dougherty County (Carter 1987)
- Lee County (Carter 1987)
- Pulaski County (Carter 1987)
- Houston County, GA (Carter 1992)
- Florida Museum of Natural History (FLMNH) holds 68 specimens
- 22 from Georgia (most by Burt Carter)
- 3 from Mitchell County
- 12 from Dougherty County
- 5 from Lee County
- 2 Crisp County
- 19 from Alabama
- 27 from Florida
- 22 from Georgia (most by Burt Carter)
- Late Eocene; Georgia, Florida, and Alabama.
- Late Eocene, Jacksonian Stage (Carter 1987)
Mellita quinquiesperforata
- Current nomenclature
Mellita quinquiesperforata
Description
Horizontal outline subcircular, usually flattened behind and weakly notched in front; upper surface nearly flat, sloping evenly in all directions from the apical system to the very thin margin; lower surface flat. Test perforated by narrow radial slots near the outer ends of the paired ambulacra and by a longer slot in the median part of the posterior inter-ambulacrum. Apical system having five small ocular pores; four genital pores at the paired interambulacral tips of the large starshaped madreporite. Petals extending about halfway to the margin, anterior paired petals slightly shorter and rounder than the others; poriferous zones about as wide as the interporiferous zones, open at the rounded tips. Peristome small, central. Periproct elongated, midway between the peristome and the posterior slot. Food grooves narrow, shallow divaricating near the peristome, the branches nearly surrounding the ambulacra, starting from five nodes, each covering twin buccal tubes. Surface covered with short acicular spines, which are longest around the perforations and on the lower surface. Usual size 50 to 100 millimeters in diameter. Pleistocene specimens are half again as large.
Occurrence
Description
Horizontal outline subcircular, usually flattened behind and weakly notched in front; upper surface nearly flat, sloping evenly in all directions from the apical system to the very thin margin; lower surface flat. Test perforated by narrow radial slots near the outer ends of the paired ambulacra and by a longer slot in the median part of the posterior inter-ambulacrum. Apical system having five small ocular pores; four genital pores at the paired interambulacral tips of the large starshaped madreporite. Petals extending about halfway to the margin, anterior paired petals slightly shorter and rounder than the others; poriferous zones about as wide as the interporiferous zones, open at the rounded tips. Peristome small, central. Periproct elongated, midway between the peristome and the posterior slot. Food grooves narrow, shallow divaricating near the peristome, the branches nearly surrounding the ambulacra, starting from five nodes, each covering twin buccal tubes. Surface covered with short acicular spines, which are longest around the perforations and on the lower surface. Usual size 50 to 100 millimeters in diameter. Pleistocene specimens are half again as large.
Occurrence
- Brunswick Canal, Gylnn County
- FLMNH holds 32 specimens
- Zero from Georgia
- 20 from Florida
- 8 from South Carolina
- 4 from Virginia
- Pleistocene to recent
Mortonis (Genus)
- Former genus which included Periarchus
Occurance;
- Bibb County, Georgia, south of Macon at Brown's Mount (Veatch & Stephenson 1911). See section 14R of this site.
- Crawford County, Georgia, Rich Hill, (Veatch & Stephenson 1911) See Section 14P of this site.
- Houston County, 1 mile north of Bonaire, same exposure which produced Basilosaurus whale fossils in 1911 report. (Veatch & Stephenson 1911)
- Houston County, south of Perry, old quarry (Veatch & Stephenson 1911)
Oligopygus haldemani
- Current nomenclature
Oligopygus haldemani
Description
Horizontal outline broadly ovate, nearly circular when young; upper surface moderately tumid; lower surface nearly flat in front, slightly turned down behind and sloping toward the peristome; margin broadly rounded. Apical system central, tumid, mono-basal, with four genital pores. Petals short, extending little more than halfway to the margin, the anterior the longest, expanding distally and open at the tips; poriferous zones narrower than the interporiferous; pores circular, conjugate; p I ate s narrow. Extrapetaliferous parts of ambulacra expanding to the margin; plates wider. Interambulacra thickened around the peristome internally. Peristome central, oval, deeply sunken in a transversely elongated pit whose anterior side stands nearly vertical and whose posterior side slopes less steeply and extends about halfway to the margin. Auricles erect; prongs erect, separate, far apart. Jaws present. Periproct small, circular, submarginal. Tubercles small, sunken. Length of figured specimen 35.8 mm, width 32 mm. height 16.4 mm.
Occurrence
Description
Horizontal outline broadly ovate, nearly circular when young; upper surface moderately tumid; lower surface nearly flat in front, slightly turned down behind and sloping toward the peristome; margin broadly rounded. Apical system central, tumid, mono-basal, with four genital pores. Petals short, extending little more than halfway to the margin, the anterior the longest, expanding distally and open at the tips; poriferous zones narrower than the interporiferous; pores circular, conjugate; p I ate s narrow. Extrapetaliferous parts of ambulacra expanding to the margin; plates wider. Interambulacra thickened around the peristome internally. Peristome central, oval, deeply sunken in a transversely elongated pit whose anterior side stands nearly vertical and whose posterior side slopes less steeply and extends about halfway to the margin. Auricles erect; prongs erect, separate, far apart. Jaws present. Periproct small, circular, submarginal. Tubercles small, sunken. Length of figured specimen 35.8 mm, width 32 mm. height 16.4 mm.
Occurrence
- Bainbridge (type from 70-foot well).
- Flint River, from Red Bluff, 6 miles above Bainbridge, to Blue Spring, 4 miles below Bainbridge. (S.W. McCallie & others)
- Chattahoochee River near A. C. L. Ry. bridge at Saffold, Early County.
- Dry Bread Shoals, Flint River, 8.5 miles below Newton.
- Baker County, GA (Carter 1987)
- Calhoun County, GA (Carter 1987)
- Early Co. GA (Carter 1987)
- Dougherty, GA (Carter 1687)
- Pulaski County, GA (Carter 1987)
- Lee County, GA (Carter 1992)
- Houston County, GA (Carter 1992)
- Florida Museum of Natural History (FLMNH) holds 336 specimens
- 1 from Georgia
- Early County (Adam Osborn)
- 334 from Florida
- 1 from Alabama
- 1 from Georgia
- Late Eocene, Jacksonian Stage (Carter 1987)
Oligopygus phelani
- Current nomenclature (Florida MNH)
- New Species (Kier 1967)
Oligopygus phelani
Description (From www.echinologia.com)
Small, elongate, width 83 to 88 percent of length, length/width ratio quite constant; in smaller specimens marginal outline oval, in large specimens sub pentagonal, pointed anteriorly, blunted posteriorly with greatest width anterior; largest specimen 18.5 mm long, average specimen 10 to 13 mm long, smallest 6.0 mm long; greatest height commonly at apical system, in some specimens anterior; height quite variable varying from 42 to 60 percent of length; adapical surface slightly convex, sides smoothly curving, adoral surface lacking deep peristomal sulcus, only depressed immediately around peristome opening.
Apical system- Central to slightly posterior; monobasal, madreporite strongly inflated, several tubercles on madreporite; ocular plates small ; four genital pores, anterior pair closer together than posterior, pores large in some specimens small in others ; not visible in any specimens smaller than 8 mm long.
Ambulacra—Petals well developed, open in some specimens, straight, slightly closing in others; interporiferous zone widest in petal III where almost twice as wide as single poriferous zone; in other petals interporiferous zone slightly wider than poriferous zone; petal III longest with from 4 to 9 more pore-pairs in single poriferous zone than petals II or IV, 4 to 7 more than petals V or I; in largest specimen, 18.5 mm long, 23 pore-pairs in single poriferous zone of petal III, in smallest specimen, 6.0 mm long, 11 pore-pairs; outer pore of pair distal to inner; pores strongly conjugate, in sutures between plates. Beyond petals, ambulacral plates single pored; at extremity of petal, pores very numerous in many included and demi plates; at ambitus pores most crowded in double series in each half-ambulacrum with continuous column of demi plates separating primary plates from adradial suture; a few included plates inserted between primaries and demi plates ; included and demi plates near adradial border, plates thin not extending through test ; nearing peristome primary plates extend to adradial suture, no included plates, one demi plate for each primary; buccal pores difficult to see.
Interambulacra —Two columns in each area except at peristome where column terminating in single plate.
Peristome —Slightly anterior, central, or slightly posterior, opening slightly wider than high, in specimen 17.5 mm long, opening 2.18 mm wide, 1.94 mm high, opening (pi. 22, fig. 5) curved anteriorly, slightly pointed posteriorly; not in deep sulcus, test only depressed in area immediately around opening.
Periproct —Small, 1.4 mm wide in specimen 17.5 mm long, slightly wider than high; located between 54 and 73 percent of the distance from center of peristome to posterior margin.
Occurrences
Description (From www.echinologia.com)
Small, elongate, width 83 to 88 percent of length, length/width ratio quite constant; in smaller specimens marginal outline oval, in large specimens sub pentagonal, pointed anteriorly, blunted posteriorly with greatest width anterior; largest specimen 18.5 mm long, average specimen 10 to 13 mm long, smallest 6.0 mm long; greatest height commonly at apical system, in some specimens anterior; height quite variable varying from 42 to 60 percent of length; adapical surface slightly convex, sides smoothly curving, adoral surface lacking deep peristomal sulcus, only depressed immediately around peristome opening.
Apical system- Central to slightly posterior; monobasal, madreporite strongly inflated, several tubercles on madreporite; ocular plates small ; four genital pores, anterior pair closer together than posterior, pores large in some specimens small in others ; not visible in any specimens smaller than 8 mm long.
Ambulacra—Petals well developed, open in some specimens, straight, slightly closing in others; interporiferous zone widest in petal III where almost twice as wide as single poriferous zone; in other petals interporiferous zone slightly wider than poriferous zone; petal III longest with from 4 to 9 more pore-pairs in single poriferous zone than petals II or IV, 4 to 7 more than petals V or I; in largest specimen, 18.5 mm long, 23 pore-pairs in single poriferous zone of petal III, in smallest specimen, 6.0 mm long, 11 pore-pairs; outer pore of pair distal to inner; pores strongly conjugate, in sutures between plates. Beyond petals, ambulacral plates single pored; at extremity of petal, pores very numerous in many included and demi plates; at ambitus pores most crowded in double series in each half-ambulacrum with continuous column of demi plates separating primary plates from adradial suture; a few included plates inserted between primaries and demi plates ; included and demi plates near adradial border, plates thin not extending through test ; nearing peristome primary plates extend to adradial suture, no included plates, one demi plate for each primary; buccal pores difficult to see.
Interambulacra —Two columns in each area except at peristome where column terminating in single plate.
Peristome —Slightly anterior, central, or slightly posterior, opening slightly wider than high, in specimen 17.5 mm long, opening 2.18 mm wide, 1.94 mm high, opening (pi. 22, fig. 5) curved anteriorly, slightly pointed posteriorly; not in deep sulcus, test only depressed in area immediately around opening.
Periproct —Small, 1.4 mm wide in specimen 17.5 mm long, slightly wider than high; located between 54 and 73 percent of the distance from center of peristome to posterior margin.
Occurrences
- Mitchell County, GA (Carter 1992)
- Relatively common in Florida but only 1 report from Georgia.
- Holotype; Citrus Co. Florida; S. bank Withlacoochee River about 50 ft. SE of Hwy. 200 bridge at Stokes Ferry.
- Florida Geol. Survey loc. 1-5377, quarry in Citrus County south of Withlacoochee River one mile west of bridge at Inglis, Levy County; spoil banks along first 4 miles of Trans-Florida Canal near Inglis.
- Many specimens held in Florida Museum of Natural History.
- FLMNH holds 37 specimens
- 1 from Georgia
- Early County (Burt Carter)
- 36 from Florida
- 1 from Georgia
- Late Eocene, Crystal River formation
Oligopygus rotundus
- Current nomenclature
Oligopygus rotundus
Description
Horizontal outline nearly circular; upper surface inflated; lower surface flatter; margin broadly rounded. Apical system central, tumid, with four genital pores, monobasal. Petals tumid; paired petals extending more than halfway to the margin, odd petal somewhat longer; poriferous zones narrow, regularly expanding, open distally; pores circular, conjugate. Peristome central, oval, at the bottom of a deep, straight-walled transverse depression occupying less than one-third the total diameter of the test. Periproct small, round, flush, near the posterior third of the lower side. Tubercles rather large, sunken; intermediate spaces granulated. Length of type 22 mm; width 20.7 mm; height 13.2 mm.
Occurrence
Oligopygus rotundus is very similar to O. collignoni from Cuba and may prove to be identical with it. The peristomial depression is' similar in shape but is smaller. A larger suite of both species is needed to determine whether this difference is an individual variation. The location of the periproct-farther from the marl gin than in 0. haldemani and closer to it than in 0. Wetherbyi and the steeper slopes of the walls of the peristomial depression distinguish Oligopygus rotundus from other North American species.
Description
Horizontal outline nearly circular; upper surface inflated; lower surface flatter; margin broadly rounded. Apical system central, tumid, with four genital pores, monobasal. Petals tumid; paired petals extending more than halfway to the margin, odd petal somewhat longer; poriferous zones narrow, regularly expanding, open distally; pores circular, conjugate. Peristome central, oval, at the bottom of a deep, straight-walled transverse depression occupying less than one-third the total diameter of the test. Periproct small, round, flush, near the posterior third of the lower side. Tubercles rather large, sunken; intermediate spaces granulated. Length of type 22 mm; width 20.7 mm; height 13.2 mm.
Occurrence
- Cooke (1959) multiple Alabama locations
- Early County, GA; Claibornian, Middle Eocene (Carter 1987)
- Florida Museum of Natural History (FLMNH) holds 11 specimens
- Zero from Georgia
- 10 from Florida
- 1 from Alabama
- Middle to Late Eocene
Oligopygus rotundus is very similar to O. collignoni from Cuba and may prove to be identical with it. The peristomial depression is' similar in shape but is smaller. A larger suite of both species is needed to determine whether this difference is an individual variation. The location of the periproct-farther from the marl gin than in 0. haldemani and closer to it than in 0. Wetherbyi and the steeper slopes of the walls of the peristomial depression distinguish Oligopygus rotundus from other North American species.
Oligopygus wetherbyi
- Current nomenclature
- Unreported in Georgia by Cooke (1959)
- Reported in the Tivola Limestone of Houston County by Sam Pickering 1970
Oligopygus wetherbyi
Description
Horizontal outline ovate to sub pentagonal; upper surface moderately inflated, sloping evenly in all directions from the central apex; margin broadly rounded; lower surface somewhat flat, with a short, wide, deep depression around the peristome. Apical system central, buttonlike, monobasal, with four genital pores. Petals straight, extending two-thirds the way to the margin, wide open distally; pores circular, conjugate; composed of narrow plates; slightly constricted at the distal end. Extrapetalous part of ambulacra widening to the margin; plates twice as wide as those in the petals. Interambulacral plates four to seven times as wide as the adjoining ambulacral plates. Peristome transversely oval, at the bottom of a deep depression; having jaws and double-pronged auricles. Periproct small, round midway between the peristome and the margin. Tubercles deeply sunken, covering entire surface except the poriferous zones; intermediate spaces granulated. Length of largest figured specimen 54 mm, width 45.5 mm, height 25.5 mm.
Occurrence
Description
Horizontal outline ovate to sub pentagonal; upper surface moderately inflated, sloping evenly in all directions from the central apex; margin broadly rounded; lower surface somewhat flat, with a short, wide, deep depression around the peristome. Apical system central, buttonlike, monobasal, with four genital pores. Petals straight, extending two-thirds the way to the margin, wide open distally; pores circular, conjugate; composed of narrow plates; slightly constricted at the distal end. Extrapetalous part of ambulacra widening to the margin; plates twice as wide as those in the petals. Interambulacral plates four to seven times as wide as the adjoining ambulacral plates. Peristome transversely oval, at the bottom of a deep depression; having jaws and double-pronged auricles. Periproct small, round midway between the peristome and the margin. Tubercles deeply sunken, covering entire surface except the poriferous zones; intermediate spaces granulated. Length of largest figured specimen 54 mm, width 45.5 mm, height 25.5 mm.
Occurrence
- Cooke does not list in Georgia.
- In 1970 (Bulletin 81) Sam Pickering reported it as very rare in the Tivola Limestone of greater Houston County. (Pickering referred to the sediments as the Ocala Limestone, they were reassigned as the Tivola Limestone.)
- The Echinoid Directory only list this species as occurring in Florida.
- Florida Museum of Natural History only reports this species from Florida.
- Burt Carter, in 1987, does not report it as occurring in Georgia.
- He would later find specimens in Georgia.
- Decatur County, GA (Carter 1992)
- Baker County, GA (Carter 1992)
- FLMNH holds 261 specimens
- 1 from Georgia
- 260 from Florida
- Tivola Limestone, Late Eocene
- Later Eocene, Jacksonian Stage (Carter 1987)
Pentedium curator
- Current nomenclature
Pentedium curator
Description
The specimen is 22 mm long, 20.2 mm wide, and 3.8 mm high. The anterior margin is curved, the posterior blunted although this may be due to fracturing. The test is low, with its width and the greatest height posterior to the apical system. The adoral surface is flat to slightly concave, the margin is sharp.
Occurrence
Geologic Unit
Description
The specimen is 22 mm long, 20.2 mm wide, and 3.8 mm high. The anterior margin is curved, the posterior blunted although this may be due to fracturing. The test is low, with its width and the greatest height posterior to the apical system. The adoral surface is flat to slightly concave, the margin is sharp.
Occurrence
- Glynn County, GA, from a 1,130 foot deep well core by the USGS near Brunswick.
- Echinoids occurred in strata identified my S.M. Herrick of the USGS as Middle Eocene Lake City Formation through foraminifera.
Geologic Unit
- Claibornian, Middle Eocene, Lake City Formation.
Periarchus lyelli
- Current nomenclature
- Genus name formerly Scutella
Periarchus lyelli
Description
Horizontal outline subcircular; upper surface slightly tumid to conical centrally, nearly flat marginally; margin usually thin; oral side flat. Apical system central; madreporite large, central; five genital pores· Petals lanceoplate, extending halfway to the margin, pen at the outer ends; poriferous zones nearly equal in width to the interporiferous; inner pores circular, outer pores elongated; pores conjugate; plates simple. Interambulacra continuous. Peristome central, circular, small; ambulacral grooves shallow, straight to the mid-radius, divaricating beyond; buccal tubes slightly projecting into the opening; granular within. Periproct less than halfway to the margin, small. Tubercles
small, sunken. Length of figured specimens 68.2-78.7 mm, width 67.2-76.0 mm, height 6.5 mm.
Description
Horizontal outline subcircular; upper surface slightly tumid to conical centrally, nearly flat marginally; margin usually thin; oral side flat. Apical system central; madreporite large, central; five genital pores· Petals lanceoplate, extending halfway to the margin, pen at the outer ends; poriferous zones nearly equal in width to the interporiferous; inner pores circular, outer pores elongated; pores conjugate; plates simple. Interambulacra continuous. Peristome central, circular, small; ambulacral grooves shallow, straight to the mid-radius, divaricating beyond; buccal tubes slightly projecting into the opening; granular within. Periproct less than halfway to the margin, small. Tubercles
small, sunken. Length of figured specimens 68.2-78.7 mm, width 67.2-76.0 mm, height 6.5 mm.
Occurrence
Geologic Unit
Remarks
- Georgia: Many localities, listed by Cooke (1942, p. 14).
- Twiggs County; Upper Parts of the Riggins Mill member of the Clinchfield Formation (Huddlestun 1986)
- Burke County, Utley Limestone at Plant Vogtle (Huddlestun 1986)
- Early County, GA, Claibornian Stage(Carter 1987)
- Glynn County, GA, Claibornian Stage (Carter 1987)
- Carter did not list this species in Jacksonian sediments (1987) though it occurs frequently.
- Calhoun County, GA (Carter 1992)
- Dougherty County, GA (Carter 1992)
- Lee County, GA (Carter 1992)
- Houston County, GA (Carter 1992)
- Multiple locations in Alabama, South & North Carolina
- Middle Eocene (Burt Carter)
- FLMNH holds 287 specimens
- 19 from Georgia
- 13 from Houston County (Burt Carter)
- 2 from Lee County (1 Burt Carter, 1 unassigned)
- 1 Calhoun County (Burt Carter)
- 1 Sumter County (Burt Carter)
- 2 no county assigned
- 56 from Alabama
- 99 from Florida
- 99 from North Carolina
- 14 from Mississippi
- 19 from Georgia
Geologic Unit
- Middle Eocene, Gosport sand and equivalents.
- Late Eocene, Jackson group.
- Tivola Limestone (rare), Houston County, GA (Pickering 1970)
- Clinchfield Sand (common), Houston County, GA (Pickering 1970)
- May occur also in the Cook County Mountain formation of Middle Eocene age and equivalents.
Remarks
- Periarchus lyelli is very abundant and variable. The typical variety occurring near Claiborne, Alabama, is low-domed but grades into the higher, conical variety pileus-sinensis. The large flat subspecies floridanus is more stable.
Periarchus pileussinensis
Also known as; Periarchus lyelli pileus-sinensis
Also known as; Periarchus lyelli pileus-sinensis
- Current nomenclature
Periarchus pileussinensis
Description
This variety differs from what may be regarded as the typical form of Periarchus lyelli in the conical shape of its petaliferous area. All gradations may be found between a high form with concave slopes resembling a volcano and the low dome-shaped typical variety common at Claiborne, Alabama. Size is similar to Periarchus lyelli.
Description
This variety differs from what may be regarded as the typical form of Periarchus lyelli in the conical shape of its petaliferous area. All gradations may be found between a high form with concave slopes resembling a volcano and the low dome-shaped typical variety common at Claiborne, Alabama. Size is similar to Periarchus lyelli.
Occurrence
- Abundant in Tivola limestone.
- Common in the Clinchfield Formation (Pickering 1970)
- Common in limestone beds of the Twiggs Clay
- Common in some exposures of the Ocmulgee Limestone, Latest Eocene, of Oaky Woods Wildlife Management Area.
- Occurs in an exposure of the Tobacco Road Sand in Oaky Woods Wildlife Management Area, the same layered exposure has beds of Periarchus quinquefarius.
- Browns Mount, Bibb County, GA (Thurman 2023)
- Florida Museum of Natural History (FLMNH) holds 109 specimens.
- 90 from Georgia
- 74 from Houston County (Roger Portell, Cemex)
- 2 from Crawford County (Burt Carter)
- 6 from Lee County (most Burt Carter)
- 1 from Twiggs County (Burt Carter)
- 1 from Early County (Adam Osborn)
- 2 from Glynn County (Chet Kirby)
- 1 from Bleckley County (Burt Carter)
- 2 from Crisp County (Burt Carter)
- 1 no county assignment
- 5 from North Carolina
- Zero from Florida
- 6 from Mississippi
- 8 from Alabama
- 90 from Georgia
- Late Eocene, Ocala limestone (east of Tombigbee River in Alabama) and Yazoo clay (west of Tombigbee River); probably also in Moodys Branch formation and equivalents.
- Latest Eocene, Ocmulgee Formation, Oaky Woods Wildlife Management Area Houston County. GA
- Latest Eocene, Tobacco Road Sand, Okay Woods Wildlife Management Area Houston County. GA.
- Latest Eocene, Sandersville Limestone (?) Browns Mount, Macon, GA.
Periarchus quinquefarius
- Current nomenclature though this is somewhat contested.
- Also known as; Mortonella quinquefaria.
- Nomenclature with Florida Museum of Natural History
- Currently only known from Georgia (under this name)
Periarchus quinquefarius
Description
Horizontal outline circular; upper surface slightly tumid centrally, sub-margin flat; margin generally rather thick or beveled, oral side flat. Apical system central, having a large central madreporite and five genital pores. Petals wide, of nearly equal lengths, extending three-quarters of the way to the margin, outer edges convex; poriferous zones wider than the interporiferous zones, closed at the apical ends, open distally; inner pores circular, in nearly straight lines; outer pores elongated; pores ·conjugate. Peristome small, circular, central; food grooves extending halfway to the margin, where the grooves bifurcate; each branch of the grooves has an outward branch extending nearly at right angles to it before curving to the margin; grooves punctate. Periproct smaller than the peristome, circular, nearly midway between the peristome and the margin. Sunken tubercles cover the entire surface, including the apical system.
Length of figured specimens 52.0, 60.0 mm; width 54.0, 62.0 mm; height 9.4, 11.5 mm.
Description
Horizontal outline circular; upper surface slightly tumid centrally, sub-margin flat; margin generally rather thick or beveled, oral side flat. Apical system central, having a large central madreporite and five genital pores. Petals wide, of nearly equal lengths, extending three-quarters of the way to the margin, outer edges convex; poriferous zones wider than the interporiferous zones, closed at the apical ends, open distally; inner pores circular, in nearly straight lines; outer pores elongated; pores ·conjugate. Peristome small, circular, central; food grooves extending halfway to the margin, where the grooves bifurcate; each branch of the grooves has an outward branch extending nearly at right angles to it before curving to the margin; grooves punctate. Periproct smaller than the peristome, circular, nearly midway between the peristome and the margin. Sunken tubercles cover the entire surface, including the apical system.
Length of figured specimens 52.0, 60.0 mm; width 54.0, 62.0 mm; height 9.4, 11.5 mm.
Occurrences
- Only known from Georgia (Current as of 2023)
- Somewhere near Milledgeville (Baldwin Co?), Clark & Twitchell, (1915) Paleobilogy Database.
- Spring and lime-sink 1 mile southwest of the courthouse at Sandersville, Washington County. (S.W. McCallie)
- Quarry of Atlantic Lime Rock Company 1.5 miles south of Sandersville.
- Limestone quarry about 1 mile southwest of Sandersville, under power lines.
- Cut on Central of Georgia Railway between mileposts 138 and 139, Washington County. (S.W. McCallie)
- Dublin road 4.6 miles southwest of Tennille, Washington County, at crossing of Central of Georgia Railway.
- 1.5 miles northwest of Tennille. (S.W. McCallie)
- T. W. Smith's farm 2.2 miles south of Warthen, Washington County. (S.W. McCallie)
- 1 mile south of Waynesboro, Burke County.
- Roadside at Hatcher's mill, 3.5 miles north of Alexander, Burke County.
- Oaky Woods Wildlife Management Area, Houston County. (Thurman 2023)
- Common in the Ocmulgee Formation (Pickering 1970)
- Houston County, GA (Carter 1992 as Mortonella quinquefaria)
- FLMNH holds 18, all from Georgia
- 18 from Georgia, Washington County ( Adam Osborne)
- Latest Eocene, Sandersville limestone.
- Latest Eocene, Ocmulgee Formation, Houston County
- Latest Eocene, Tobacco Road Sand, Houston County
- Late Eocene, Jacksonian Stage (Carter 1987)
- Periarchus quinquefarius can readily be distinguished from Periarchus lyelli and varieties by its proportionally longer petals, its usually thicker margin, and by its deeper and more conspicuous ambulacral grooves.
- This species occupies a somewhat higher horizon than Periarchus lyelli-pileussinensis. (No longer true, it was shown in 1978 & 2019 to share a bed in Okay Woods Wildlife Management Area, Houston County, GA.)
- It is known only from Georgia. Old labels referring it to Alabama are in error because of Louis Agassiz's confusion of this species with Clypeaster rogersi, whose type came from near Claiborne, Alabama.
- Say's statement that his species is abundant "near Milledgeville” is true only in a very broad sense, for Milledgeville is built on un-fossiliferous rocks of the Piedmont.
- Both Periarchus pileussinensis and Periarchus quinquefarius occur separately in layered beds of a 10 foot section of Tobacco Road Sand in Oaky Woods Wildlife Management, Houston County GA. This is the only known location where both species occur. These were originally observed in 1978 by Huddlestun and Hetrick & confirmed in 2019 by Thurman, Burt Carter, Huddlestun and Hank Josey.
Periarchus quinquefarius kewi
- Current nomenclature (somewhat contested)
- Florida Museum of Natural History lists as Mortonella quinquefaria kewi
Periarchus quinquefarius kewi
Description
Horizontal outline circular; upper surface tumid medially, swollen beyond the petals, sloping steeply to the margin; margin thin; oral side flat. Other features as in the typical variety.
Description
Horizontal outline circular; upper surface tumid medially, swollen beyond the petals, sloping steeply to the margin; margin thin; oral side flat. Other features as in the typical variety.
Occurrence
- Highway US 341, 4.2 miles southeast of Clinchfield, Houston County.
- S. W. Smith's farm 2.25, miles south of Warthen, Washington County.
- Washington County, GA (Sandersville Limstone)
- FLMNH Holds 1 from Florida
- as Mortonella quinquefaria kewi
- Latest Eocene, Sandersville Limestone (Moderately common)
- Latest Eocene, Ocmulgee Formation (rare)
- The author (Thurman) once saw & handled a Ocmulgee Formation specimen of this species in Sam Pickering’s collection.
- Periarchus kewi is here considered a variety of P. quinquetarius because it is associated with the typical form, whose margin shows a tendency to become beveled. The distinguishing features of the variety are the strongly tumid central region, the swollen sub-margin, and the plainly beveled edge.
Phyllacanthus mortoni
- Current Nomenclature
Phyllacanthus mortoni
Description (as written)
Test large, maximum known horizontal diameter about 75 mm. Apical system subcircular, larger than peristome. Ambulacra nearly uniform in width, ribbonlike; poriferous zones about twice as wide as the interporiferous zones; pores round or oval, conjugate; zygopores transverse, separated by a ridge; interporiferous zones granular. Interambulacra composed of about 8-10 tiers of plates, the median area somewhat sunken; plates wider than high; tubercles smooth, perforated, high; granules arranged in transverse rows, separated by a groove. Peristome pentagonal, the angles truncated at the ambulacra. Disconnected spines from near Albany, Georgia, where Phyllacanthus mortoni is the only cidarid known, are decorated with longitudinal rows of spinelets. On some the spinelets are uniform in size; others have longer thornlike spinelets at regular intervals.
Occurrences
Description (as written)
Test large, maximum known horizontal diameter about 75 mm. Apical system subcircular, larger than peristome. Ambulacra nearly uniform in width, ribbonlike; poriferous zones about twice as wide as the interporiferous zones; pores round or oval, conjugate; zygopores transverse, separated by a ridge; interporiferous zones granular. Interambulacra composed of about 8-10 tiers of plates, the median area somewhat sunken; plates wider than high; tubercles smooth, perforated, high; granules arranged in transverse rows, separated by a groove. Peristome pentagonal, the angles truncated at the ambulacra. Disconnected spines from near Albany, Georgia, where Phyllacanthus mortoni is the only cidarid known, are decorated with longitudinal rows of spinelets. On some the spinelets are uniform in size; others have longer thornlike spinelets at regular intervals.
Occurrences
- Near Palmyra, Lee County type of C. mortoni.
- Flint River at bridge of Seaboard Railway west of Coney, Crisp County. (S.W. McCallie)
- North of Albany Cidaris georgiana,
- Flint River at Dry Bread Shoals
- Flint River at Normans Ferry
- Newton road 7.75 miles from Bainbridge (S.W. McCallie)
- Bainbridge
- Rare in the Clinchfield Formation of Houston County. (Pickering 1970, Bulletin 81)
- Common in the Tivola Limestone, Houston County, (Pickering 1970, Bulletin 81)
- Decatur County, GA (Carter 1987)
- Dougherty County, GA (Carter 1987)
- Mitchell County, GA (Carter 1987)
- Crisp County, GA (Carter 1987)
- Houston County, GA (Carter 1987)
- Pulaski County, GA (Carter 1987)
- Crawford County, Rich Hill
- (Thurman & Hank Josey 2017)
- Florida Museum of Natural History (FLMNH) holds 117 specimens
- 6 from Georgia (all Burt Carter)
- 4 from Lee County
- 2 from Doughtery County
- 108 from Florida
- 3 from Alabama
- 6 from Georgia (all Burt Carter)
Geologic Unit
- Middle & Late Eocene (Alabama, Georgia, and Florida)
- Phyllacanthus mortoni is larger, when mature, than any other cidarid from the Eastern States. Its ambulacra are straighter, its zygopores are wider and more nearly transverse, and its pores are more conspicuously conjugated. Its ambulacra are more constricted along the median suture; a feature that becomes more conspicuous with increasing size.
- There is considerable variation in the coarseness of its granulation. The granules on the type of a. carolinensis are coarser than those of 0. mitchellii, which are more like the average specimen from Georgia.
Plagiobrissus curvus
- Current nomenclature.
Plagiobrissus curvus
Description
Test thin, ovate, margin rounded. Apical system slightly anterior. Anterior ambulacrum narrow, slightly depressed; plates nearly equilateral. Petals flush; anterior pair widely diverging, nearly straight, narrowing near the tips.; posterior pair curving backward to an angle of about 30°, the inner edge nearly straight; pores oval, strongly conjugate; poriferous zones nearly closed distally, fairly wide; interporiferous equaling the poriferous at the middle, diminishing in width at each end. Peristome at the anterior third. Periproct terminal, large, pear shaped, higher than wide, vertical. Peripetalous fasciole without lateral sinuations, slightly bent backward at the anterior end and more strongly bent backward at the posterior end. Subanal fasciole wider, apparently heart shaped, indications of an anal branch. Large perforated, crenulated tubercles confined within the peripetalous fasciole in the paired interambulacra. Plastron extending to the labrum. The outer edges of posterior ambulacra parallel on lower surface. Length of type about 58mm, width 49 mm, height 22mm.
Occurrence;
Description
Test thin, ovate, margin rounded. Apical system slightly anterior. Anterior ambulacrum narrow, slightly depressed; plates nearly equilateral. Petals flush; anterior pair widely diverging, nearly straight, narrowing near the tips.; posterior pair curving backward to an angle of about 30°, the inner edge nearly straight; pores oval, strongly conjugate; poriferous zones nearly closed distally, fairly wide; interporiferous equaling the poriferous at the middle, diminishing in width at each end. Peristome at the anterior third. Periproct terminal, large, pear shaped, higher than wide, vertical. Peripetalous fasciole without lateral sinuations, slightly bent backward at the anterior end and more strongly bent backward at the posterior end. Subanal fasciole wider, apparently heart shaped, indications of an anal branch. Large perforated, crenulated tubercles confined within the peripetalous fasciole in the paired interambulacra. Plastron extending to the labrum. The outer edges of posterior ambulacra parallel on lower surface. Length of type about 58mm, width 49 mm, height 22mm.
Occurrence;
- Flint River at mouth of Kinchafoonee Creek above Albany.
- Flint River at Bainbridge
- Decatur, County (Carter 1987)
- Dougherty County (Carter 1987)
- Calhoun County, GA (Carter 1992)
- Lee County, GA (Carter 1992)
- Florida Museum of Natural History (FLMNH) holds 20 specimens
- 7 from Georgia
- 3 from Dougherty County (Burt Carter & Roger Portell)
- 2 from Houston County (Burt Carter)
- 2 from Decatur County (unattributed)
- 13 from Florida
- 7 from Georgia
- Late Eocene, Jacksonian Stage (Carter 1987)
Plagiobrissus dixie
- Uncertain Identification by Cooke (1959)
- Current nomenclature
Plagiobrissus dixie
Description
Test oval, depressed, truncate behind, margin rounded, upper surface little more inflated than the lower, rostrate above the periproct. Apical system slightly anterior; four genital pores; ethmolytic, the madreporite extending behind the ocular plates. Anterior ambulacrum not petaloid nor depressed, narrow, plates nearly equilateral. Petals plainly depressed; anterior pair widely spreading, curving forward; posterior pair, straight, diverging at an angle of 50°, somewhat longer than the anterior pair; pores oval, conjugate; anterior poriferous zone of anterior petals narrowing toward the apex. Ambulacra on under side narrow; outer edges of posterior pair parallel. Paired interambulacra excluded from the peristome. Plastron wide, connected with the labrum. Peristome large, sub-oval, lip nearly flat. Periproct large, pear shaped, visible from above. Peripetalous fasciole narrow, weakly reentrant behind. Subanal fasciole heart shaped, wider than long; no anal projections detected. Large tubercles confined within the peripetalous fasciole.
Length of holotype 47.3 mm; width 38.5 mm; height 21.6 mm. Length of figured specimen 79 mm; width 68.5 mm; heigh~ 27 mm.
Occurrence
Description
Test oval, depressed, truncate behind, margin rounded, upper surface little more inflated than the lower, rostrate above the periproct. Apical system slightly anterior; four genital pores; ethmolytic, the madreporite extending behind the ocular plates. Anterior ambulacrum not petaloid nor depressed, narrow, plates nearly equilateral. Petals plainly depressed; anterior pair widely spreading, curving forward; posterior pair, straight, diverging at an angle of 50°, somewhat longer than the anterior pair; pores oval, conjugate; anterior poriferous zone of anterior petals narrowing toward the apex. Ambulacra on under side narrow; outer edges of posterior pair parallel. Paired interambulacra excluded from the peristome. Plastron wide, connected with the labrum. Peristome large, sub-oval, lip nearly flat. Periproct large, pear shaped, visible from above. Peripetalous fasciole narrow, weakly reentrant behind. Subanal fasciole heart shaped, wider than long; no anal projections detected. Large tubercles confined within the peripetalous fasciole.
Length of holotype 47.3 mm; width 38.5 mm; height 21.6 mm. Length of figured specimen 79 mm; width 68.5 mm; heigh~ 27 mm.
Occurrence
- Georgia: Small island in Flint River about 2.5 miles below Cedar Creek, Crisp County.
- Dam on Flint River at Kinchafoonee Creek north of Albany.
- Miller County, GA (Carter 1987)
- Dougherty County, GA (Carter 1992)
- Lee County (Carter 1992)
- Miller County, GA (Carter 1992)
- Crisp County, GA Carter 1992)
- FLMNH holds 49 specimens
- 4 from Georgia
- 2 Lee County (Burt Carter)
- 1 Mitchell County (Burt Carter)
- 1 Dougherty County (Andrew May)
- 45 from Florida
- 4 from Georgia
- Late Eocene, Jacksonian Stage (Carter 1987)
- The reference of this species to Plagiobrissus is questioned because no evidence of the presence of animal fasciole has been found. Moreover, the anterior petals curve forward whereas those of Plagiobrissus· grandis curve slightly backward. The species is removed from Eupatagus because of the narrowness of the ambulacra and the length of the plastron. The type of Eupatagus ftoridanus is an internal mold. It has the general appearance of this species except that its petals do not curve forward. The description of E. floridanus was based on two other specimens, which are here referred to Eupatagus antillarum.
Plagiochasma cruciform
- Cooke’s assigned genus Rhopostoma is reassigned as Plagiochasma
- Plagiochasma cruciferum is current nomenclature.
Plagiochasma cruciform
Description (as written)
Horizontal outline oval; upper surface unevenly inflated, sloping more steeply forward than backward; lower surface rounded, concave around the peristome; margin broadly rounded. Apical system anterior; four genital plates, all perforated; madreporite central, not extending behind the posterior ocular plates; ocular plates fairly large, posterior pair separated by small interambulacral plates. Ambulacra narrow, not expanding toward the margin, not petaliferous; plates apparently simple throughout though becoming higher toward the peristome; pore pairs transverse and fairly wide near the apex, becoming oblique and narrower distally. Interambulacral plates about three times as high as ambulacral. Peristome subtriangular, oblique, longest dimension extending from left anterior to right posterior as viewed from below. Periproct large, pyriform, supramarginal, opening into a broad, shallow sulcus, which indents the margin. Tubercles fairly large, sunken. Length of type 26.5 mm; width 23 mm; height 15mm.
Description (as written)
Horizontal outline oval; upper surface unevenly inflated, sloping more steeply forward than backward; lower surface rounded, concave around the peristome; margin broadly rounded. Apical system anterior; four genital plates, all perforated; madreporite central, not extending behind the posterior ocular plates; ocular plates fairly large, posterior pair separated by small interambulacral plates. Ambulacra narrow, not expanding toward the margin, not petaliferous; plates apparently simple throughout though becoming higher toward the peristome; pore pairs transverse and fairly wide near the apex, becoming oblique and narrower distally. Interambulacral plates about three times as high as ambulacral. Peristome subtriangular, oblique, longest dimension extending from left anterior to right posterior as viewed from below. Periproct large, pyriform, supramarginal, opening into a broad, shallow sulcus, which indents the margin. Tubercles fairly large, sunken. Length of type 26.5 mm; width 23 mm; height 15mm.
Occurrence
- New Jersey (Zachos 2017)
- Georgia; Clayton Formation, Wade Pit, 0.5 mile west of US 27, 1.75 miles south of Stewart-Randolph
- County line, Randolph County, Georgia
- Other localities in New Jersey, Alabama, Arkansas, and Georgia (Clayton Fm.)
- Internal mold, possibly this species, 9 miles southeast of Lumpkin.
- Wade Quarry, Randolph County (Burt Carter)
- Sumter County (P. Dupree, Burt Carter)
- Paleocene
Rhyncholampas conradi
- Current Nomenclature
- (FL Nat Hist Museum & Echinoid Directory UK agree)
- Formerly Cassidulus conradi (Cooke 1959)
- 1959 sub-species listed as Cassidulus conradi lyelli
- 1959 sub-species listed as Cassidulus (Plagiopygus) conradi
- Cooke used Cassidulus (Plagiopygus) conradi (1959)
- There is some nomenclature confusion
Rhyncholampas conradi
Description
Horizontal outline oval usually somewhat compressed posterolaterally, upper surface evenly tumid, rostrate above the periproct; lower surface usually slightly concave around the peristome; margin broadly rounded. The apical system anteriorly eccentric, monobasal, with four genital pores. Petals long and rather straight, open distally; inner poriferous zones of paired petals longer than the outer; inner pores circular, outer pores oval. Peristome large, pentagonal, wider than long, nearer the center than the apical system; phyllodes nearly as wide as long, bourrelets elongated, swollen, granulated. Periproct terminal, at the top of a narrow vertical truncation, wider than high. Tubercles depressed, small on upper surface, larger on lower; covering entire test except a narrow pitted band behind the peristome.
Length of type 40.8 mm; width 34 mm; height 22.7 mm. Length of figured specimen 41.4; width 35.2 height 20 mm.
Occurrence
Description
Horizontal outline oval usually somewhat compressed posterolaterally, upper surface evenly tumid, rostrate above the periproct; lower surface usually slightly concave around the peristome; margin broadly rounded. The apical system anteriorly eccentric, monobasal, with four genital pores. Petals long and rather straight, open distally; inner poriferous zones of paired petals longer than the outer; inner pores circular, outer pores oval. Peristome large, pentagonal, wider than long, nearer the center than the apical system; phyllodes nearly as wide as long, bourrelets elongated, swollen, granulated. Periproct terminal, at the top of a narrow vertical truncation, wider than high. Tubercles depressed, small on upper surface, larger on lower; covering entire test except a narrow pitted band behind the peristome.
Length of type 40.8 mm; width 34 mm; height 22.7 mm. Length of figured specimen 41.4; width 35.2 height 20 mm.
Occurrence
- Palmyra, Lee County (label specifies only Georgia).
- Kinchafoonee Creek 2 or 3 miles north of Albany.
- About 5 miles west of Colquitt Ichawaynochaway Creek about 4 miles west of Newton, Baker County (internal mold).
- Decatur County, GA (Carter 1987)
- Baker County, GA (Carter 1987)
- Dougherty County, GA (Carter 1987)
- Lee County, GA (Carter 1987)
- Miller County, GA (Carter 1987)
- Crisp County, GA (Carter 1992)
- Florida Museum of Natural History (FLMNH) holds 285 specimens
- 43 from Georgia
- 12 from Lee County (Burt Carter)
- 8 from Crisp County (Burt Carter)
- 1 from Seminole County (Burt Carter)
- 1 from Baker County (Burt Carter)
- 21 from Dougherty County
- (Burt Carter, Adam Osborn, Muriel Hunter, & Llyod Glawe)
- 190 from Florida
- 52 from Alabama
- 43 from Georgia
- Late Eocene, Jacksonian (Carter 1987)
Rhyncholampas ericsoni
- Current nomenclature
- Formerly Cassidulus ericsoni (Cooke 1959)
Rhyncholampas ericsoni
Description
Horizontal outline subovate, wider behind. Upper surface strongly inflated, highest in front of the apical system, rostrate above the periproct. Lower surface flat. Margin acute. Apical system monobasal, with four genital pores. Petals lanceolate, extending about halfway to the margin, open distally; inner poriferous zones of paired petals longer than the outer. Peristome directly below the apical system, small, pentagonal, wider than long; phyllodes nearly as wide as long; bourrelets globular. Periproct small, transverse, supramarginal, near the posterior fourth, opening into a long, wide, shallow sulcus, which indents the margin. Tubercles sunken, small on upper surface, much larger on lower surface. Median band in front of and behind the peristome without tubercles. Length of paratype, 45.5 mm; width 41.2 mm; height 29.7 mm.
Occurrence
Rhyncolampus ericsoni is larger, proportionally shorter, wider, and higher than R. trojanus Cooke and has proportionately smaller peristomel and periproct. It is similar to R. gouldii in general appearance, but its periproct is much farther forward.
Description
Horizontal outline subovate, wider behind. Upper surface strongly inflated, highest in front of the apical system, rostrate above the periproct. Lower surface flat. Margin acute. Apical system monobasal, with four genital pores. Petals lanceolate, extending about halfway to the margin, open distally; inner poriferous zones of paired petals longer than the outer. Peristome directly below the apical system, small, pentagonal, wider than long; phyllodes nearly as wide as long; bourrelets globular. Periproct small, transverse, supramarginal, near the posterior fourth, opening into a long, wide, shallow sulcus, which indents the margin. Tubercles sunken, small on upper surface, much larger on lower surface. Median band in front of and behind the peristome without tubercles. Length of paratype, 45.5 mm; width 41.2 mm; height 29.7 mm.
Occurrence
- Cooke only reported from Florida in 1959
- Early County, GA (Carter 1987)
- Lee County, GA (Carter 1992)
- FLMNH holds 38 specimens
- 1 from Georgia
- Lee County (Burt Carter)
- 37 from Florida
- 1 from Georgia
- Late Eocene, Jacksonian Stage (Carter 1987)
Rhyncolampus ericsoni is larger, proportionally shorter, wider, and higher than R. trojanus Cooke and has proportionately smaller peristomel and periproct. It is similar to R. gouldii in general appearance, but its periproct is much farther forward.
Rhyncholampas georgiensis
- Current nomenclature
- 1959 nomenclature Cassidulus (Plagiopygus) georgiensis
Rhyncholampas georgiensis
Description
Horizontal outline subquadrate, widest near the posterior end, not much longer than wide; upper surface variably inflated, highest point ranging from behind the apical system (type) to in front of it, slightly rostrate above the periproct; oral surface nearly flat; margin
sub-acutely to broadly rounded; widest part usually above the margin. Apical system anteriorly eccentric, mono basal, with four genital pores; petals lanceolate extending about halfway to the margin, not very wide; pores circular or oval; poriferous zones unequally long, the inner zones of the paired petals longer than the outer. Peristome directly beneath the apical system, rather large, pentagonal, wider than long; phyllodes almost straight sided, nearly as wide as long; bourrelets elongated, wall-like. Periproct wider than long, terminal, well above the margin. Tubercles depressed, much smaller on top than underneath; covering entire test except a wide pitted longitudinal band on lower surface.
Occurrence
Description
Horizontal outline subquadrate, widest near the posterior end, not much longer than wide; upper surface variably inflated, highest point ranging from behind the apical system (type) to in front of it, slightly rostrate above the periproct; oral surface nearly flat; margin
sub-acutely to broadly rounded; widest part usually above the margin. Apical system anteriorly eccentric, mono basal, with four genital pores; petals lanceolate extending about halfway to the margin, not very wide; pores circular or oval; poriferous zones unequally long, the inner zones of the paired petals longer than the outer. Peristome directly beneath the apical system, rather large, pentagonal, wider than long; phyllodes almost straight sided, nearly as wide as long; bourrelets elongated, wall-like. Periproct wider than long, terminal, well above the margin. Tubercles depressed, much smaller on top than underneath; covering entire test except a wide pitted longitudinal band on lower surface.
Occurrence
- Bainbridge.
- Red Bluff, Flint River, 6 miles above Bainbridge.
- Chattahoochee River at A. C. L. Ry. bridge near Saffold, Early County.
- Decatur County (Carter 1987)
- Early County (Carter 1987)
- Lee County (Carter 1987)
- Calhoun County, GA (Carter 1987)
- Florida Museum of Natural History (FLMNH) holds 34 specimens
- 9 from Georgia
- 6 from Lee County (Burt Carter)
- 1 from Early County (not attributed)
- 1 from Calhoun County (Burt Carter)
- 1 from Houston County (Burt Carter)
- 25 from Florida
- 9 from Georgia
- Late Eocene, Jacksonian (Carter 1987)
Rhyncholampas gouldii
- Current nomenclature
- Reassigned from; Cassidulus gouldii
Rhyncholampas gouldii
Description
Horizontal outline subovate, weakly truncated in front and behind, wider behind. Upper surface inflated, highest point near the front, tending to be sub-conical; rostrate above the periproct. Lower surface is nearly flat. Margin subacute. Apical system somewhat anterior; madreporite central, large; four genital pores. Petals rather long, extending more than halfway to the margin, lanceolate, open distally, somewhat swollen; inner poriferous zones of paired petals longer than the outer; pores oval, conjugate or not. Peristome farther forward than the apical system, pentagonal, wider than long; phyllodes longer than wide, bourrelets swollen. Periproct supramarginal, at the posterior fifth, transverse, opening into a well-defined sulcus, which indents the margin. Tubercles depressed, small on upper surface, much larger and deeply depressed on lower surface. Median area on lower surface bare Length of figured specimen 45 mm; width 40.6 mm; height 22 mm.
Description
Horizontal outline subovate, weakly truncated in front and behind, wider behind. Upper surface inflated, highest point near the front, tending to be sub-conical; rostrate above the periproct. Lower surface is nearly flat. Margin subacute. Apical system somewhat anterior; madreporite central, large; four genital pores. Petals rather long, extending more than halfway to the margin, lanceolate, open distally, somewhat swollen; inner poriferous zones of paired petals longer than the outer; pores oval, conjugate or not. Peristome farther forward than the apical system, pentagonal, wider than long; phyllodes longer than wide, bourrelets swollen. Periproct supramarginal, at the posterior fifth, transverse, opening into a well-defined sulcus, which indents the margin. Tubercles depressed, small on upper surface, much larger and deeply depressed on lower surface. Median area on lower surface bare Length of figured specimen 45 mm; width 40.6 mm; height 22 mm.
Occurrence
- Baker County (type). 2.5 miles north of Cuthbert. (S.W. McCallie)
- A. E. Belcher's well in lot 180, 16th District, Decatur County. (S.W. McCallie)
- Leesburg
- Flint River 0.5 mile below Newton.
- Georgia Southern and Florida Railway 32 miles south of Macon. (S.W. McCallie)
- 2 miles south of Perry.
- Hawkinsville. (Bleckley County)
- Abbeville road 3.5 miles south of Hawkinsville.
- 9 miles southwest of Abbeville and 0.5mile northeast of Center School, Wilcox County.
- Albany Road 9 miles north of Camilla.
- Houston, Pulaski Counties, Oligocene residuum, Common (Flint River Formation, Pickering 1970)
- Red Dog Farm Road, Bleckley County. (Thurman 2020)
- Southern Burke County, GA, in numbers, exposed by natives Americans seeking chert for tools. (2022 Sept, Stan Smith)
- Micthell County, GA (Carter 1987)
- Sumter County, GA (Carter 1987)
- Pulaski County, GA (Carter 1987)
- FLMNH holds 866 specimens
- 21 from Georgia
- 1 Georgia specimen with no county attributed (Miriam Hicks)
- 1 from Terrell County (Burt Carter)
- 1 from Bleckley County (Red Dog Farm Rd, Thurman?)
- 1 from Dougherty County (Burt Carter)
- 1 from Macon County (Burt Carter)
- 2 from Crisp County (Burt Carter)
- 2 from Sumter County (Burt Carter)
- 2 from Brantley County (Chet Kirby)
- 6 from Mitchell County
- (Burt Carter, Muriel Hunter, Jeremy Hart, & Jon Bryan)
- 824 from Florida
- 18 from Mississippi
- 3 unattributed
- 21 from Georgia
Geologic Unit
- Early Oligocene
- Mint Spring marl member of the Marianna limestone of middle Oligocene age, in Mississippi.
- Byram limestone of middle Oligocene age and Suwannee limestone of late Oligocene age, in Florida
- Flint River formation (reassigned as Oligocene Undifferentiated Chert) of Early Oligocene age in Georgia.
- Early Oligocene, Vicksburgian Stage (Carter 1987)
- Late Oligocene, Chickasawhayan Stage, Sumter & Pulaski Counties, GA. (Carter 1987)
Rhyncholampas trojana
- Reassigned from Eurhodia trojanus by Rich Mooi
- Reassigned from Cassidulus trojanus by Burt Carter & Thomas Biesel (1987)
- Also referred to as Eurhodia trojanus.
Rhyncholampas trojana
Description
Outline subquadrate, wider behind than in front. The upper surface moderately inflated except behind the periproct, where there is a broad, shallow sulcus; rostrate above the periproct. Lower surface flat. Margin acute. Apical system slightly eccentric anteriorly; four genital pores; madreporite central. Petals lanceolate, of nearly equal length, extending somewhat more than halfway to the margin, open at the distal ends; pores round or oval; interporiferous zones wider than poriferous zones; outer poriferous zones of paired petals longer than the inner. Peristome farther forward than the apical system, pentagonal, slightly wider than long. Oral lobes swollen. Phyllodes about as long as the diameter of the peristomial opening. Periproct supramarginal, transversely elliptical, flush, about one-third the way from the margin to the apex. Upper surface finely granulated between small tubercles; tubercles on lower surface much larger than on the upper, deeply sunken except· on the margin, where they are much smaller. Longitidunal median band on base moderately wide, deeply pitted. Length 25.4 mm; width 22 mm.; height 11.4 mm.
Occurence
Description
Outline subquadrate, wider behind than in front. The upper surface moderately inflated except behind the periproct, where there is a broad, shallow sulcus; rostrate above the periproct. Lower surface flat. Margin acute. Apical system slightly eccentric anteriorly; four genital pores; madreporite central. Petals lanceolate, of nearly equal length, extending somewhat more than halfway to the margin, open at the distal ends; pores round or oval; interporiferous zones wider than poriferous zones; outer poriferous zones of paired petals longer than the inner. Peristome farther forward than the apical system, pentagonal, slightly wider than long. Oral lobes swollen. Phyllodes about as long as the diameter of the peristomial opening. Periproct supramarginal, transversely elliptical, flush, about one-third the way from the margin to the apex. Upper surface finely granulated between small tubercles; tubercles on lower surface much larger than on the upper, deeply sunken except· on the margin, where they are much smaller. Longitidunal median band on base moderately wide, deeply pitted. Length 25.4 mm; width 22 mm.; height 11.4 mm.
Occurence
- Miller County about 1 mile southeast of Joe Shingler and about 5 miles west of Colquitt.
- Spring Creek at Colquitt
- Calhoun County, GA (Carter 1987)
- Crisp County, GA (Carter 1992)
- Late Eocene, Jacksonian (Carter 1987)
Salenia palmyra
- Current nomenclature?
- Could not confirm in other databases.
- New species (Zachos 2017)
Salenia palmyra
Description
Test small, slightly rounded above and flattened aborally. Apical disc rounded, ~70% of test diameter, low in profile. Two or three distinct pits along genital-genital, genital-ocular, and suranal plate sutures. All apical disc plates smooth and lacking granules. Periproct sub trigonal, at junction of genital plates 1 and 5 and suranal plate, separated from ocular plate I. All oculars excerpt. Ambulacra strictly bigeminate with hardly any pore crowding adorally. Columns of primary ambulacral tubercles separated by less than the diameter of one tubercle: no discernible secondary tubercles perradially. Interambulacra with five or six plates in a column. Inter-radial
zone narrow with few granules outside the scrobicular ring. Peristome ~40% of test diameter, with small notches.
Occurrence
Description
Test small, slightly rounded above and flattened aborally. Apical disc rounded, ~70% of test diameter, low in profile. Two or three distinct pits along genital-genital, genital-ocular, and suranal plate sutures. All apical disc plates smooth and lacking granules. Periproct sub trigonal, at junction of genital plates 1 and 5 and suranal plate, separated from ocular plate I. All oculars excerpt. Ambulacra strictly bigeminate with hardly any pore crowding adorally. Columns of primary ambulacral tubercles separated by less than the diameter of one tubercle: no discernible secondary tubercles perradially. Interambulacra with five or six plates in a column. Inter-radial
zone narrow with few granules outside the scrobicular ring. Peristome ~40% of test diameter, with small notches.
Occurrence
- Georgia; Clayton Formation, Wade Pit, 0.5 mile west of US 27, 1.75 miles south of Stewart-Randolph County line, Randolph County.
- Alabama; Resource Management Services Palmyra tract, west of State Highway 263, entrance 2 miles north of Butler-Lowndes County line, Lowndes County, Alabama
- Florida Museum of Natural History (FLMNH) hold 44 specimens
- 2 from Georgia
- 1 from Crisp County (Burt Carter)
- 1 from Decatur County (Burt Carter)
- 42 from Florida
- 2 from Georgia
- Early Paleocene, Danian Stage, Clayton Formation, McBryde Member (Zachos 2017)
- The presence of smooth apical plates readily distinguishes this species from S. tumidula. Carter (1997) attributed three small test fragments collected from the Salt Mountain Limestone to Salenia? but the figured plates lack the secondary tubercles observed on both S. palmyra & S. tumidula. These fragments are indeterminate and no other species of Salenia are known from the Paleocene of the eastern United States.
Schizaster americanus
- Current nomenclature (Florida MNH)
- Formerly Paraster americanus (Cooke 1959)
Schizaster americanus
Description
Horizontal outline subcircular, indented in front, highest behind, sloping to the rounded margin; truncated behind. Apical system slightly posterior; four genital pores, the two posterior pores far apart, the anterior pair near the posterior; madreporite extending between and beyond the genital pores. Petals deeply, sunken; the anterior pair nearly twice as long as the posterior pair, straight, diverging at an angle of' nearly 90°; the posterior twisted to an angle approximating 37°; pores of paired petals far apart, interporiferous zones about the same width. Anterior sulcus extending to the peristome. Peristome at the anterior third, reniform, covered by a protruding rimmed lip. Periproct high on the posterior truncation. Peripetalous fasciole deeply indented; lateral fascioles straight, meeting below the periproct.
Length of type 39 mm; width 38.5 mm; height 25.5mm.
Description
Horizontal outline subcircular, indented in front, highest behind, sloping to the rounded margin; truncated behind. Apical system slightly posterior; four genital pores, the two posterior pores far apart, the anterior pair near the posterior; madreporite extending between and beyond the genital pores. Petals deeply, sunken; the anterior pair nearly twice as long as the posterior pair, straight, diverging at an angle of' nearly 90°; the posterior twisted to an angle approximating 37°; pores of paired petals far apart, interporiferous zones about the same width. Anterior sulcus extending to the peristome. Peristome at the anterior third, reniform, covered by a protruding rimmed lip. Periproct high on the posterior truncation. Peripetalous fasciole deeply indented; lateral fascioles straight, meeting below the periproct.
Length of type 39 mm; width 38.5 mm; height 25.5mm.
Occurrence
- Georgia, Ocmulgee River .75 miles downstream from Mile Branch Boat landing in Hawkinsville, Marianna Limestone. (Cooke 1959)
- Pulaski County, GA (Carter 1987)
- Cook County, GA (D.T. Dockery 1980)
- Probable error, Source, Paleobiology Database, (Paleobiodb.org) Reference: D. T. Dockery. 1980. Invertebrate Macropaleontolgy of the Clarke County Mississippi Area. Bulletin 122, Mississippi Geological, Economic and Topographic Survey
- FLMNH holds 20 specimens
- Zero from Georgia
- 8 from Florida
- 5 from Alabama
- 7 from Mississippi Geologic unit
- Early Oligocene, Vicksburgian Stage (Carter 1987)
Schizaster armiger
- Current Nomenclature
- Reassigned from Paraster armiger
Schizaster armiger
Description
Horizontal outline sub-rhombic, longer than wide, indented in front; highest behind, curving gradually downward to the margin, truncated behind. Apical system slightly posterior; four genital pores, the posterior pair far apart, the anterior pair somewhat smaller and closer together, very near the posterior pair; madreporite extending between and beyond the posterior ocular plates. Petals deeply depressed; paired petals extending about three-fourths of the radius; anterior pair the longer, straight or slightly flexuous, diverging at an angle of nearly 90°; posterior pair curved together to an angle of 35°; pores large, oval, strongly conjugate; interporiferous zones about as wide as poriferous. Pores of anterior petal small, circular, pairs slightly inclined; interporiferous zones wide. Peristome at the anterior quarter, lunate, covered by a projecting rimmed lip. Periproct terminal, high on the posterior truncation, longer than wide. Peripetalous fasciole deeply indented; lateral fascioles gently curved to their junction well below the periproct. Anterior ambulacral furrow extending to the peristome. Posterior ridge terminating at the periproct. Length of figured specimen 58 mm; width 52.5 mm; height 36.5 mm.
Occurrence, Georgia
Geologic unit.
Remarks.
Description
Horizontal outline sub-rhombic, longer than wide, indented in front; highest behind, curving gradually downward to the margin, truncated behind. Apical system slightly posterior; four genital pores, the posterior pair far apart, the anterior pair somewhat smaller and closer together, very near the posterior pair; madreporite extending between and beyond the posterior ocular plates. Petals deeply depressed; paired petals extending about three-fourths of the radius; anterior pair the longer, straight or slightly flexuous, diverging at an angle of nearly 90°; posterior pair curved together to an angle of 35°; pores large, oval, strongly conjugate; interporiferous zones about as wide as poriferous. Pores of anterior petal small, circular, pairs slightly inclined; interporiferous zones wide. Peristome at the anterior quarter, lunate, covered by a projecting rimmed lip. Periproct terminal, high on the posterior truncation, longer than wide. Peripetalous fasciole deeply indented; lateral fascioles gently curved to their junction well below the periproct. Anterior ambulacral furrow extending to the peristome. Posterior ridge terminating at the periproct. Length of figured specimen 58 mm; width 52.5 mm; height 36.5 mm.
Occurrence, Georgia
- Bank of Muckafoonee Greek near its confluence with Flint River, about 1.5 miles above Albany.
- Power plant on Kinchafoonee Creek 2 miles north of Albany.
- Flint River at the northeast corner of Dougherty County.
- Lee County, GA, (Burt Carter 1987)
- Crisp County, Lake Blackshear (Burt Carter & Yonnie Williams)
- Dougherty County (Burt Carter 1987)
- Ocmulgee Formation, rare (Pickering 1970)
- Pulaski County, GA (Carter 1987)
- Houston County, GA (1992)
- Florida Museum of Natural History (FLMNH) holds 111 specimens
- 19 from Georgia
- 5 from Crisp County (Burt Carter)
- 9 from Dougherty County (Burt Carter & unattributed)
- 4 from Lee County (Burt Carter)
- 1 from Houston County (Penn Dixie Cement, now Cemex)
- 21 from Alabama
- 71 from Florida
- 19 from Georgia
Geologic unit.
- Late Eocene, Jacksonian Stage (Carter 1987)
Remarks.
- The type and other specimens from western Alabama have wider petals than those from Florida. There is some variation in the relative length of the posterior petals.
Scutella (Genus)
- Historic nomencalture
Scutella (Genus)
- Reassigned as Periarchus & Mortonella
- See Periarchus for description
- Jefferson County, reported in 1911 by Veatch & Stephenson in Jefferson County.
- Confirmed by Hank Josey, and Identified as Periarchus quinquefarius in peronal communication, but not published in the literature.
- The author is not aware of any modern, published reports on echinoids in Jerrfon County, GA
Comments
- Mentions of "Scutella" or "Scutella beds" are often encountered in the historic literature, this could refer to any of the above ilustrated species.
Thylechinus (Gagaria) chickasawhay
- Cannot confirm current nomenclature
- Genus Thylechinus listed with Florida Museum of Natural History & The Echinoid Directory (UK)
- But the species is not listed,
- Unreported in Georgia by Cooke
- Pickering (1970) reported (very rare) in Houston County area as Gagaria chickasawhay.
Thylechinus (Gagaria) chickasawhay
Description
Test of medium size. Oculogenital ring and peristome unknown. Ambulacra with two rows of large crenulate, imperforate tubercles, each tubercle surrounded by a squared ring of small tubercles; pore pairs uniserial, nearly straight, three pairs in each compound plate; pores of each pair separated by a granule. Interambulacra wider, with two contiguous median rows of crenulate, imperforate large tubercles and one row of smaller tubercles on each margin, each large tubercle enclosed in a ring of little tubercles. Detached spines long, slender, cylindrical, slightly swollen near the tip, smooth when perfect but longitudinally corrugated when slightly corroded. Larger spines flattened, spoon-shaped.
Occurrences
Description
Test of medium size. Oculogenital ring and peristome unknown. Ambulacra with two rows of large crenulate, imperforate tubercles, each tubercle surrounded by a squared ring of small tubercles; pore pairs uniserial, nearly straight, three pairs in each compound plate; pores of each pair separated by a granule. Interambulacra wider, with two contiguous median rows of crenulate, imperforate large tubercles and one row of smaller tubercles on each margin, each large tubercle enclosed in a ring of little tubercles. Detached spines long, slender, cylindrical, slightly swollen near the tip, smooth when perfect but longitudinally corrugated when slightly corroded. Larger spines flattened, spoon-shaped.
Occurrences
- Mississippi (Cooke 1959)
- Georgia; greater Houston County, Ocmulgee Formation (Pickering 1970)
- Pickering reported as very rare in the Cooper Marl, reassigned as Ocmulgee Formation.
- Mississippi; Early Oligocene
- Georgia; Late Eocene
Weisbordella cubae
- Current nomenclature (Florida Museum of Natural History)
Weisbordella cubae
Description
Test oval; upper surface more or less convex; lower surface slightly concave; margin rounded. Apical system central or anterior; four small genital pores, usually obscure, moderately far apart; hydropores confined to small crooked grooves. Petals wide, short, pointed, extending little more than half the radius, nearly closed at the tips; plates compound, structure complex; poriferous zones narrow, slightly incurved at the apical end but wide apart there and almost touching the adjacent petals; inner pores punctate, outer pores elongate. Peristome small, central, pentagonal, usually retaining the teeth. Periproct transversely oval, about one fourth the radius from the margin. Tubercles sunken, those on the upper surface rather widely spaced; small except a central cluster of larger ones between the genital pores; a few large adventitious tubercles present or not on the interambulacra; tubercles on the oral surface larger than the ordinary ones on the upper surface. Length of holotype 13 mm; width 12 mm; height 2.5 mm. Length of figured specimen 19.6 mm; width 17.6 mm; height 5.3 mm. Length of figured specimen 44.6 mm; width 40 mm; height 10.9 mm.
Occurrence
Description
Test oval; upper surface more or less convex; lower surface slightly concave; margin rounded. Apical system central or anterior; four small genital pores, usually obscure, moderately far apart; hydropores confined to small crooked grooves. Petals wide, short, pointed, extending little more than half the radius, nearly closed at the tips; plates compound, structure complex; poriferous zones narrow, slightly incurved at the apical end but wide apart there and almost touching the adjacent petals; inner pores punctate, outer pores elongate. Peristome small, central, pentagonal, usually retaining the teeth. Periproct transversely oval, about one fourth the radius from the margin. Tubercles sunken, those on the upper surface rather widely spaced; small except a central cluster of larger ones between the genital pores; a few large adventitious tubercles present or not on the interambulacra; tubercles on the oral surface larger than the ordinary ones on the upper surface. Length of holotype 13 mm; width 12 mm; height 2.5 mm. Length of figured specimen 19.6 mm; width 17.6 mm; height 5.3 mm. Length of figured specimen 44.6 mm; width 40 mm; height 10.9 mm.
Occurrence
- East bank Flint River at mouth of creek in northeast corner of Dougherty Co.
- Dougherty County, GA (Carter 1992)
- Lee County, GA (Carter 1992)
- Florida Museum of Natural History holds 183 specimens
- 1 from Georgia
- Lee County (Robert Hammock)
- 182 from Florida
- 1 from Georgia
- Late Eocene, Jacksonian Stage (Carter 1987)
- The number of large adventitious tubercles on Weisbordella cubae is variable; some individuals have more than the figured specimens, many have none.
Weisbordella johnsoni
- Current Nomenclature (Florida Museum of Natural History)
Weisbordella johnsoni
Description
Horizontal outline sub-oval; upper surface tumid; lower surface concave; margin swollen, round. Apical system slightly anterior; four genital pores rather close together; hydro pores confined to crooked grooves. Petals lanceolate, long, narrow, extending more than two-thirds the radius; plates compound; poriferous zones moderately open at the apical end, nearly closed distally; inner pores punctate, outer pores elongate. Peristome slightly anterior, small, pentagonal, teeth usually preserved. Periproct small, circular, about one third the radius from the margin. Tubercles small, sunken, closer on upper surface than on lower. Length of holotype 33.2 mm; width 30.0 mm; height 9.5 min. A specimen from Florida measures 54.4 by 49.0 by 11.0 millimeters.
Occurrences
Description
Horizontal outline sub-oval; upper surface tumid; lower surface concave; margin swollen, round. Apical system slightly anterior; four genital pores rather close together; hydro pores confined to crooked grooves. Petals lanceolate, long, narrow, extending more than two-thirds the radius; plates compound; poriferous zones moderately open at the apical end, nearly closed distally; inner pores punctate, outer pores elongate. Peristome slightly anterior, small, pentagonal, teeth usually preserved. Periproct small, circular, about one third the radius from the margin. Tubercles small, sunken, closer on upper surface than on lower. Length of holotype 33.2 mm; width 30.0 mm; height 9.5 min. A specimen from Florida measures 54.4 by 49.0 by 11.0 millimeters.
Occurrences
- Bainbridge (S.W. McCallie)
- Flint River at Red Bluff, 6 miles above Bainbridge.
- Flint River at spring 2 miles below Normans Ferry, Mitchell, County.
- Flint River at Dry Bread Shoals 9 miles below Newton.
- Powerplant 2 miles north of courthouse at Albany.
- Well at Cordele, depth 225-feet. (S.W. McCallie)
- Decatur County, GA (Carter 1987)
- Baker County, GA (Carter 1987)
- Dougerty County, GA (Carter 1987)
- Micthell County, GA (Carter 1987)
- Crisp County, GA (Carter 1987)
- Lee County, GA (Carter 1987)
- Calhoun County, GA (Carter 1992)
- Houston County, GA (Carter 1992)
- FLMNH holds 87 specimens
- 13 from Georgia
- 3 from Houston County (Burt Carter)
- 5 from Lee County (Burt Carter)
- 1 from Baker County (William Tiejen)
- 1 from Calhoun County (Burt Carter)
- 1 from Sumter County (Joseph Summerour)
- 1 from Dougherty County (Adam Osborn)
- 1 from Mitchell County (Burt Carter)
- 32 from Florida
- 41 from Alabama
- 1 from Mexico
- 13 from Georgia
- Late Eocene, Jacksonian Stage (Carter 1987)
- This species is the same as that identified as Scutella crustuloides Morton (1833) by Clark and Twitchell (1915) but the type of that species is lost. Weisbordella johnsoni is evidently not the species first figured by Morton (1833), which may be a Protoscutella. The petals of W. johnsoni are wider open at the apex than those of the latter figure by Morton (1834). According to Morton (1834) Scutella crustuloides "is found in considerable numbers in the calcareous strata of South Carolina." Weisbordella johnsoni has not been found in South Carolina.
Wythella eldridgei
- Current Nomenclature
- Only two reports from Georgia, 1959 & 1970
- Florida Museum of Natural History has no Georgia specimens
Wythella eldridgei
Description
Horizontal outline sub-oval, usually truncated in front, behind, and in posterior ambulacra; upper surface low, slightly tumid centrally, some specimens having tumidities near the proximal ends of the ambulacra apparently caused by pressure of the jaws; lower surface flat, food grooves bifurcating; margin thin. Apical system so mew hat anterior; four (sometimes three) genital pores; madreporic pores in crooked grooves. Petals lanceolate, the anterior the longest, the anterior pair the shortest and widest; plates compound; poriferous zones wide, inner pores oval, outer pores elongated, zones closed distally, slightly open apically, where the ocular plates protrude between the zones. Interambulacra terminating in a single large plate at the apex. Peristome sub-oval, wider than long. Periproct large, circular, one-third the way from the margin to the peristome. Tubercles sunken, smaller on upper side than on lower.
Length of type 94.0 mm; width 7 4.1 mm; height 11.1 mm.
Description
Horizontal outline sub-oval, usually truncated in front, behind, and in posterior ambulacra; upper surface low, slightly tumid centrally, some specimens having tumidities near the proximal ends of the ambulacra apparently caused by pressure of the jaws; lower surface flat, food grooves bifurcating; margin thin. Apical system so mew hat anterior; four (sometimes three) genital pores; madreporic pores in crooked grooves. Petals lanceolate, the anterior the longest, the anterior pair the shortest and widest; plates compound; poriferous zones wide, inner pores oval, outer pores elongated, zones closed distally, slightly open apically, where the ocular plates protrude between the zones. Interambulacra terminating in a single large plate at the apex. Peristome sub-oval, wider than long. Periproct large, circular, one-third the way from the margin to the peristome. Tubercles sunken, smaller on upper side than on lower.
Length of type 94.0 mm; width 7 4.1 mm; height 11.1 mm.
Occurrence
- Many Florida locations
- Georgia, left bank of Flint River at Mitchell-Doughtery County line.
- Pulaski County (Carter 1987)
- Tivola Limestone, very rare, Houston County, GA (Pickering 1970)
- Mitchell County, GA (Carter 1992)
- Florida Museum of Natural History (FLMNH) holds 115 specimens.
- All from Florida
- No Georgia Specimens
- Late Eocene, Jacksonian (Carter 1987)
References
- Cooke, C. Wythe; Cenozoic Echinoids of the Eastern United States, Geologic Survey Professional Paper 321, U.S. Dept of Interior, USGS, 1959
- Florida Museum of Natural History, Collection Directory, Invertebrate Paleontology; Web Portal (ufl.edu)
- Natural History Museum (London), The Echinoid Directory; The Echinoid Directory - Natural History Museum (nhm.ac.uk)
- Encyclopedia of Life, Smithsonian, National Museum of Natural History Encyclopedia of Life (eol.org)
- Enchinologia, a French site about fossil echinoids, echinologia.com/galeries/oligopygidae/index.html
- Carter, Burchard D. & McKinney, Michael L.; Eocene Echinoids of the Suwannee Strait, and Biogeographic Taphonomy, Paleobiology 18 (3), Pg 299-325, 1992
- Carter, Burchard D.; Paleogene Echinoid Distributions in the Atlantic and Gulf Coastal Plains; Palaios, 1987, v.2, pgs. 390-404, The Society of Economic Paleontologists and Geologists
- Carter, Burchard D.; McKinney, Michael L.; Eocene Echinoids, The Suwannee Strait, and biogeographic taphonomy; Paleobiology, 183(2), 1992, pp. 299-325
- Huddlestun, Paul F., & Hetrick, John H.; Upper Eocene Stratigraphy of Central and Eastern Georgia, Georgia Department of Natural Resources, Environmental Protection Division, Bulletin 95. 1986.
- Pickering, Sam M.; Stratigraphy, Paleontology, and Economic Geology of Portions of Perry and Cochran Quadrangles. The Geological Survey of Georgia, Department of Mines, Mining and Geology, Bulletin 81. 1970.
- Huddlestun, Paul F.; The Oligocene, A Revision of the Lithostratigraphic Units of the Coastal Plain of Georgia; Bulletin 105, Georgia Geologic Survey, 1993
- Zachos, Louis G.; Paleocene Echinoid Faunas of the Eastern United States, Journal of Paleontology, 91 (3), 2017, Pg. 1001-1024
- Cook, Robert B.; Minerals of Georgia Their Properties & Occurrences, Bulletin 92, Georgia Geological Survey, 1978
- Kier, Porter M.; Echinoids from the Middle Eocene Lake City Formation in Georgia, Smithsonian Institute Press, Washington DC, 1968
- Veatch, Otto; Stephenson, Lloyd William; Preliminary Report on the Geology of the Coastal Plain of Georgia; US Geological Survey, Georgia Geological Survey, Bulletin 26, 1911
- The Paleobiology database; PBDB Navigator (paleobiodb.org)