14S: Late Eocene Snakes and a Frog
From the Twiggs Clay
of Twiggs County, Georgia
By Thomas Thurman
26/July/2026
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In 1977 J. Alan Holman reported two new species of Late Eocene boa constrictors, plus sea snakes and a frog, from fossils which Dr. Michael Voorhies had cataloged while he was a professor at UGA. These were from the Twiggs Clay of Twiggs County Georgia. Both marine and terrestrial animals are represented so an estuary or tropical coastline seems indicated. One new species of boa was named for Dr. Michael Voorhies, a well-deserved honor. Let me thank Asa Kaplan now for his assistance in obtaining a copy of this paper. |
At the time of this report Holman was with Michigan State University Museum in East Lansing, Michigan. Voorhies had recently left the University of Georgia and was at the University of Nebraska State Museum following up on his Nebraska Ashfall Beds discovery.
Sadly, though these fossils were once held in the UGA collection, they're now lost and no longer available for review and the images from the 1977 paper are the only images in existence.
Reported Fossils
The fossil sketches on this webpage are adapted from the original paper which credits Merald Clark and Barbara Gudgeon as the artists. I separated the species, highlighted the scale bars, added numbers, and descriptions for clarity. The fossil images themselves were not modified in any way.
The fossil sketches on this webpage are adapted from the original paper which credits Merald Clark and Barbara Gudgeon as the artists. I separated the species, highlighted the scale bars, added numbers, and descriptions for clarity. The fossil images themselves were not modified in any way.
Frog
Genus; Eopelobates (possible) Extinct
University of Georgia Vertebrate Paleontology (UGV) #46
Class Amphibia, Order Anura.
Family; Palobatidae
No images provided
Paleobatids include toads and frogs and are distinct for the spade-like structures on their hind feet. Holman specifically calls this specimen a frog in the text.
Material collected
Left ilium; hip bone
Partial tibiofibular; leg bone & joint
Partial humerous; leg bone
Genus; Eopelobates (possible) Extinct
University of Georgia Vertebrate Paleontology (UGV) #46
Class Amphibia, Order Anura.
Family; Palobatidae
No images provided
Paleobatids include toads and frogs and are distinct for the spade-like structures on their hind feet. Holman specifically calls this specimen a frog in the text.
Material collected
Left ilium; hip bone
Partial tibiofibular; leg bone & joint
Partial humerous; leg bone
Sea Snakes
Species, Palaeophis virginianus Extinct
Sea snake represented by a single vertebra
Specimen UGV #53
Single vertebra (imaged)
Family, Palaeophiidae (Palaeophiid)
There was debate at the time of this paper whether this genus should be classified as a lizard or snake but showed that the vertebra were unquestionably snakes, there were far more snake- like features when compared to monitor lizards.
Species, Palaeophis virginianus Extinct
Sea snake represented by a single vertebra
Specimen UGV #53
Single vertebra (imaged)
Family, Palaeophiidae (Palaeophiid)
There was debate at the time of this paper whether this genus should be classified as a lizard or snake but showed that the vertebra were unquestionably snakes, there were far more snake- like features when compared to monitor lizards.
Species; Pterosphenus schucherti Extinct
Large sea snake represented by two vertebrae.
Specimen# UGV 52a
Large vertebra (imaged)
Specimen# UGV 52b
Small vertebra (No known image exists)
Both vertebrae are well preserved but the larger one is remarkably well preserved and easily assignable to the species.
Boa Constrictors
Huberophis georgiensis (New Genus & Species)
Specimen# UGV 51
Single vertebra
Named for the small, unincorporated town of Huber, Georgia. Huber is also a major kaolin company and there is the famous, large Huber Formation deposited between the Paleocene and Eocene. Holman speculates that this snake is descended through a common unknown ancestor with the smaller boa (boid) genus Calamagras.
This species still stands as current and is listed in the Paleobiology Database.
Huberophis georgiensis (New Genus & Species)
Specimen# UGV 51
Single vertebra
Named for the small, unincorporated town of Huber, Georgia. Huber is also a major kaolin company and there is the famous, large Huber Formation deposited between the Paleocene and Eocene. Holman speculates that this snake is descended through a common unknown ancestor with the smaller boa (boid) genus Calamagras.
This species still stands as current and is listed in the Paleobiology Database.
Ogmophis voorhiesi (New species)
Specimen# UGV 47, UGV 48, UGV 49
Vertebrae (3)
Only UGV 47 is imaged
Named in honor of Dr. Michael Voorhies
This species still stands as current and is listed in the Paleobiology Database.
This species is also reported from Wyoming, previously known specimen was reassigned to this species.
Specimen# UGV 47, UGV 48, UGV 49
Vertebrae (3)
Only UGV 47 is imaged
Named in honor of Dr. Michael Voorhies
This species still stands as current and is listed in the Paleobiology Database.
This species is also reported from Wyoming, previously known specimen was reassigned to this species.
Pit 22
These fossils were among the mammalian fossils Voorhies had placed on the UGA collection which included an entelodont tooth originally identified as a siren (dugong or manatee). Voorhies never published the siren tooth, and it wasn’t identified as an entelodont until 1982. (See Page 14O of this website.) The presence of an entelodont tooth would seem to support an estuary environment. (Sadly, no known illustration or photo of the entelodont tooth exists.) The fossils Holman reported and the entelodont came from Huber Pit 22 which was abandoned at the time but has since been reclaimed. Sadly, collection is no longer possible at this site.
These fossils were among the mammalian fossils Voorhies had placed on the UGA collection which included an entelodont tooth originally identified as a siren (dugong or manatee). Voorhies never published the siren tooth, and it wasn’t identified as an entelodont until 1982. (See Page 14O of this website.) The presence of an entelodont tooth would seem to support an estuary environment. (Sadly, no known illustration or photo of the entelodont tooth exists.) The fossils Holman reported and the entelodont came from Huber Pit 22 which was abandoned at the time but has since been reclaimed. Sadly, collection is no longer possible at this site.
Holman describes the Pit 22 collection site as “approximately 9 mi SSE of Macon and 4 mi ENE of Huber, Twiggs County, Georgia. The fossils were recovered from a lens of red sandy clay 50 ft above the base of the Twiggs Clay.”
It might be worthwhile to explore the area for other possible outcrops of a sandy red sand lens near the top of the Twiggs Clay.
It might be worthwhile to explore the area for other possible outcrops of a sandy red sand lens near the top of the Twiggs Clay.
There is some confusion in the histories. Voorhies didn’t collect the entelodont tooth. I spoke to Voorhies by telephone about this very issue some years ago, thirty years after the entelodont tooth was identified. It was given to Voorhies by Bill Christy, a well-known amateur of the day who often worked with Voorhies and the mines.
In 1977 Voorhies dated the fossils to the Duchesnean Stage of the North American Land Mammal Age, that would place the fossils in the Late Eocene between 40.1 to 37.0 million years ago. Later research (1986) by Paul F Huddlestun and John H. Hetrick, identified foraminifera from the Twiggs Clay which current research dates to between 34.35 to 35.42 million years ago. The Eocene ended 33.9 million years ago with a large glacial event and the extinction of many species.
I typically date the Twiggs to about 35 million years. Since 1977 scientists have improved their understanding of foraminifera and sharpened their ability to date sediments.
I typically date the Twiggs to about 35 million years. Since 1977 scientists have improved their understanding of foraminifera and sharpened their ability to date sediments.
Stratigraphy, Huber Pit 22
Holman references 1972 research by Robert E. Carver over the Eocene stratigraphy of east Georgia. Specifically, the section drawing Carver produced of the exposure in Pit 22.
Holman references 1972 research by Robert E. Carver over the Eocene stratigraphy of east Georgia. Specifically, the section drawing Carver produced of the exposure in Pit 22.
This “lens of sandy red clay” was 50 feet above the Tivola Limestone, in Unit 13 of the section.
Carver’s somewhat confusing description of Section 3. (Lightly edited for clarity)
Section#3, J.M. Huber Corp. Pit No. 22, approximately 4 miles ENE of Huber, Twiggs County, Georgia. Teeth of elasmobranchs (sharks and rays) are very abundant in parts of the spoil bank bordering the pit. The teeth appear to be from unit 2 or 3. (Probably from the Clinchfield Sand is historically rich in shark teeth.)
Middendorf Formation, unit 1, abundant and varied borings in the upper part of the unit; Clinchfield Sand, grading irregularly upward into the Ocala (reassigned as Tivola Limestone) Limestone, units 2 through 7; sandy nodular limestones of the Tivola Limestone grading upwards into the Twiggs Clay, units 8 through 10; calcareous Twiggs Clay with hard limy sub-units and nodular lenses in upper part, units 11 through 14; Unit 13 is interlaminated sand and clay of the Irwinton Sand interfingering with the Twiggs Clay.
Section#3, J.M. Huber Corp. Pit No. 22, approximately 4 miles ENE of Huber, Twiggs County, Georgia. Teeth of elasmobranchs (sharks and rays) are very abundant in parts of the spoil bank bordering the pit. The teeth appear to be from unit 2 or 3. (Probably from the Clinchfield Sand is historically rich in shark teeth.)
Middendorf Formation, unit 1, abundant and varied borings in the upper part of the unit; Clinchfield Sand, grading irregularly upward into the Ocala (reassigned as Tivola Limestone) Limestone, units 2 through 7; sandy nodular limestones of the Tivola Limestone grading upwards into the Twiggs Clay, units 8 through 10; calcareous Twiggs Clay with hard limy sub-units and nodular lenses in upper part, units 11 through 14; Unit 13 is interlaminated sand and clay of the Irwinton Sand interfingering with the Twiggs Clay.
In his discussion of the Twiggs Clay (Page 167) Carver reports that Unit 13 of Section 3 “contains sponge spicules, foraminifera, ostracods, bryozoans, and abundant oysters.” Bryozoans and oysters are very uncommon in the Twiggs Clay in most places.
Acknowledgements
Holman finishes the paper by thanking “Dr. Michael Voorhies of the University of Nebraska State Museum for privilege of studying the fossils collected by him while at the University of Georgia. Voorhies also supplied the information about the location and age of the site. Merald Clark and Barbara Gudgeon made the drawings.”
Holman finishes the paper by thanking “Dr. Michael Voorhies of the University of Nebraska State Museum for privilege of studying the fossils collected by him while at the University of Georgia. Voorhies also supplied the information about the location and age of the site. Merald Clark and Barbara Gudgeon made the drawings.”
References
- Holman, J. Alan; Upper Eocene Snakes (Reptilia, Serpentes) from Georgia Journal of Herpetology, 11(2):141-145, 1977.
- 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.
- Carver, Robert E.; Stratigraphy of the Jackson Group in Eastern Georgia; Southeastern Geology 14:153-181, 1972