Exploring Georgia's Fossil Record & Our History of Paleontology
  • Items of Interest
    • Presentation; Oaky Woods Stratigraphy
    • I, Periarchus (A Fossil's Tale)
    • Coastal Plain Correlation Chart
    • Black & White Sketches
    • Contributing Artists
    • Public Fossil Locations >
      • South Houston County Fossils
      • Updated; Islands of the Savannah River
    • Georgia's Amateurs >
      • Amateur; Jared Dyche, On The Way To A Degree
      • Cam Muskelly, Duluth, GA
      • Kyle Keller, Valdosta, GA >
        • Kyle Keller Returns, Still Rocking!
      • Hank Josey, Dublin
      • Thomas Thurman, Warner Robins, GA
      • Bill Christy; Kamin Performance Minerals Fossils
    • Origins Of This Site
    • Georgia Fossils in the Smithsonian
  • Education Material
    • Georgia's State Fossil; Shark Teeth
    • Taking Georgia's Paleontology To Georgia's Classrooms
    • Georgiacetus Presentation; A Whale for Georgia
    • SW GA RESA 2018 Talk
    • Library & School Presentations
    • An Introduction To Fossils; Presentation
    • Georgia's Fossils Presentation; 500 million years
    • Free Fossils for GA Science Teachers; Crassostrea gigantissima
    • Georgia College Natural History Museum
  • Georgia's Lost Meteorite
  • Evolution in Georgia's Fossil Record
  • 1: Georgia's Oldest Fossils; Archaeocyathids, At 513 Million Years Old
  • 2: Trilobites; 500 Million Years Ago
    • 2A; Murray County Stromatolites
    • 2B; A Trilobite Nest in Georgia
  • 3: Geologic Time
  • 4: Our Oldest Vertebrate?
  • 5: Georgia Before the Dinosaurs
    • 5A; Georgia’s Pennsylvanian Plant Fossils
  • 6: 200 Million Years Ago
    • 6A: Birth of the Atlantic Ocean
  • 7: Cretaceous Georgia, Dinosaurs & more
    • 7A: Georgias Pterosaur
    • 7B: So Many Sharks
    • 7C: Coelecanths
    • 7D: Xiphactinus vetus
    • 7E: Side-necked turtles
    • 7F: Marine Reptiles
    • 7G: Dinosaurs in Georgia
    • 7H: Deinosuchus (Terrible Crocodile)
    • 7I; The Blufftown Formation
  • 8: Suwannee Current, Gulf Trough, & Bridgeboro Limestone
  • 9: The Clayton Formation Report; By Hank Josey
    • 9A: The Georgia Turtle
  • 10: The Eocene; Georgia's Oldest Mammals
    • 10A: The Origins of Whales
  • 11: A Whale For Georgia
  • 12: Basilosaurids; The First Modern Whales
    • 12A: Basilosaurus cetoides
    • 12B: Basilotritus
    • 12C: Cynthiacetus
    • 12D: Chrysocetus
    • 12E: The Redmond Mandible of Albany Ga
    • 12F; Houston County Basilosaurus to the Smithsonian
  • 13: Ziggy and The Museum of Arts & Sciences, Macon, GA
  • 14: Late Eocene
    • 14A: Eocene Fossils & Stratigraphy
    • 14B; Fossils, Impacts & Tektites Dating the Clinchfield Formation
    • 14C: The Tivola Limestone
    • 14D: Twiggs Clay Vertebrates
    • 14E: Ocmulgee Formation Vertebrates
    • 14F; Sandersville Limestone, By Hank Josey
    • 14I: Dating Late Eocene Sediments
    • 14J: Georgia's Tektites; Georgiaites
    • 14K; Shell Bluff; Georgia's Most Historic Paleontology Site
    • 14L; Taylors Bluff, Paleo Paddling the Ocmulgee River
    • 14M; Eocene Terrestrial Mammals From Gordon, GA
    • 14N: Fossil Ridge, A Stratigraphic Study in Oaky Woods Wildlife Management Area
    • 14O; Georgia's First Entelodont
  • 15: Early Oligocene
    • 15A: The Marianna Limestone
    • 15B; The Glendon Limestone
    • 15C: Undiffereniated Oligocene Residuum
    • 15D; Brissus bridgeboroensis; A New Echinoid Species From Georgia’s Bridgeboro Limestone
    • 15E: The Curious Steinkern Sea Biscuits of Red Dog Farm Road
  • 16: Bonaire GA Entelodont
  • 17: The Whale Eating Shark
  • 18: Miocene Epoch; 23.3 to 5.3 Million Years Ago
    • 18A; Miocene Terrestrial Vertebrates
    • 18B; Paul Fell, Rockhouse Cave
  • 19: Pliocene Epoch; 5.3 to 2.5 Million years Ago
  • *NEW* 19A; Two Small Primitive Horses from Taylor County
  • 20: The Ice Ages; Pleistocene & Holocene Epochs
    • 20A; Clark Quarry's Mammoths & Bison
    • 20B: Pleistocene Vertebrate List
    • 20C: Georgia’s Eolian Dunes
    • 20D: Georgia’s Carolina Bays
    • 20E: Late Pleistocene Significant Events
    • 20F: Southeastern Thermal Enclave
    • 20G; Diamond Back Terrapins
    • 20H; A Kaolin Mine Beaver Dam
    • 20I; Pleistocene Vertebrate Fossils On Georgia’s Piedmont
  • *NEW* 20J; Watkins Quarry Pleistocene Vertebrates, Glynn County, GA
  • 21: Humans in Georgia
  • 22: Geology of the Coastal Plain, 1911
    • 22A: 1911 Cretaceous Fossil Locations
    • 22B: 1911 Eocene Fossil Locations
  • 23: Coastal GA Locations (1957)
  • 24: Needed; The Georgia Geologic Survey

15D; Brissus bridgeboroensis
A New Species
from Georgia’s Bridgeboro Limestone
& the oldest known member of the genus.


A paper review by
Thomas D. Thurman
Filed; 26/April/2020
​

Picture
Picture
In 1987 Dr. Burt Carter, from Georgia Southwestern (GSW), reported a new species of extinct, early Oligocene heart urchin from the Bridgeboro Limestone of southwest Georgia. Carter published his find in the September issue of the prestigious Journal of Paleontology.  Today, Burt Carter is a Professor of Paleontology at GSW and still a student of Georgia’s deep past. Brissus bridegboroensis is the oldest known member of the genus in the eastern USA. There are older members of the genus is the Caribbean, and probably an older member in Europe. 

Picture
​Earlier that same year, Carter and J.P. Manker, also at GSW, had published an especially important paper using the uncounted rhodoliths of the Bridgeboro Limestone to prove the speculated existence of both the Gulf Trough and Suwannee Current in Georgia’s natural history. They showed the strength and approximate dimensions locally of the Suwannee current when the Bridgeboro formed. (See Section 8 of this same website) The Suwannee Current existed for tens of millions of years and carved the Gulf Trough.
Picture
​Carter discovered the heart urchin (echinoid) in the Bridgeboro Limestone quarry of Mitchell, County, GA. The Bridgeboro has been dated to the Rupelian Stage (Vickburgian) of the Oligocene Epoch and is thus dated from 28.4 to 33.9 million years old. The specimen occurred about 1 meter below the upper contact of the Bridgeboro Limestone with the overlying rhodolith-free limestone.
Picture
Carter reported that the specimen was found upright, but no spines were present. The matrix was a carbonate sandy gravel or gravelly sand, the rhodoliths present were greatly reduced in both size and population.
 
It is noted in the 1987 paper that modern species of Brissus occur in very similar conditions; Brissus latecarinatus of the Indo-Pacific is reported as buried in the gound in coarse gravel, under stones or coral slabs. Brissus unicolor of the Gulf of Mexico & West Indies lives buried in the sand near reefs. Brissus obesus is reported buried in the sand and gravel in the Gulf of California. 
Picture
The specimen collected by Carter is assigned as the species holotype. The aboral surface (surface opposite to the mouth) is excellently preserved and many details are easily observed. The margins are not as well preserved having been exposed to some crushing and dissolution. “As a result the general shape of the periproct is known but the details are obscure.” The specimen’s oral surface is obliterated. Nothing certain can be said of the peristome, though it apparently was similar to that of B. unicolor in shape and position.    
Picture
Picture
Diagnosis of the new species based defined by the holotype.
Specimen to be deposited in the U.S. National Museum of Natural History (Smithsonian) as specimen PAL402062.
​
“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”)


In 1959 C. Wythe Cooke published Cenozoic Echinoids of the Eastern United States through the USGS. In it he described & imaged all the fossil echinoids from the last 66 million years which were known in 1959. Cooke reported two species of Brissus echinoids occurring: Brissus glenni & Brissus unicolor, images and measurements of both are included.
Picture
Picture
A few more have since been reported, but Georgia’s own Brissus bridegboroensis is the oldest known member of the genus. 
​

​
​References:
  1. Carter, Burchard D., Brissus bridgeboroensis, A New Spatangoid Echinoid From the Lower Oligocene of Southwestern Georgia, Journal of Paleontology, V.61, No.5, Pages 1043-1046, 2 figs, September 1987
  2. Cooke, Wythe C., Cenozoic Echinoids of the Eastern United States, USGS, US Department of the Interior, United States Government Printing Office, 1959