5C: Mississippian Trilobites in Northwest Georgia
Describing the New Species
Australosutura georgiana
By
Thomas Thurman
01/March/2025
In 1966 Mark Rich from the University of Georgia reported the discovery of “abundant trilobite remains” in Early Mississippian aged Lavender Shale at the foot of White Oak Mountain in Catoosa County, Georgia. The discovery was made during a UGA field trip and seems to represent a significant deposit of fragmentary trilobites. A population of a new species was discovered and described from the silty claystone and silty clay shale.
Bear in mind, these fossils are small. The holotype imaged above is only about 9mm (.35”) wide. The Lavender Shale is a member of the Fort Payne Chert.
Rich states; “Most of the trilobites belong to the new species Australosutura georgiana and the remainder belong to at least 2 species of Preotus. Rich reports that the Australosutura georgiana specimens represent the first reports of the genus from the Appalachians.
It’s rare indeed for a paleontologist to discover a population of a new species. Multiple individuals…
The Mississippian Period is a span of geological time from 323 to 358 million years ago. It was very warm and sea levels were very high so that most continents were drowned. Also important was the mountain building episode which raised the Appalachians. North America collided with Gondwana, buckling, compressing and folding the terrain. This led to the rising of the Appalachian Mountains which is shown, in the maps, as an island across North Georgia.
The trilobites were found in the Lavender Shale Member of the Fort Payne Chert formation near Ringgold. Rich wrote two separate papers on this discovery and outcrop, the second was published in 1973 and by then he was dating the sediments to the Early Mississippian, 346 to 358 million years ago. The second paper reported plant and trilobite remains from the outcrop.
Thanks Asa
I want to thank Asa Kaplan for alerting me to these papers and sharing copies, I know Asa through Facebook’s Georgias Fossils Group, which I established some years ago. The group has grown to more than 11,000 members currently and Asa’s posts in the group are always thoughtful and appreciated.
I want to thank Asa Kaplan for alerting me to these papers and sharing copies, I know Asa through Facebook’s Georgias Fossils Group, which I established some years ago. The group has grown to more than 11,000 members currently and Asa’s posts in the group are always thoughtful and appreciated.
1966
Returning to the original 1966 paper. Rich reported that the species holotype was placed in Havard’s Museum of Comparative Zoology (MCZ) for permanent housing (catalog# 110939). Additional study specimens were housed in the paleontological collections of the Department of Geology at the University of Georgia, but the UGA specimens are now considered lost.
Returning to the original 1966 paper. Rich reported that the species holotype was placed in Havard’s Museum of Comparative Zoology (MCZ) for permanent housing (catalog# 110939). Additional study specimens were housed in the paleontological collections of the Department of Geology at the University of Georgia, but the UGA specimens are now considered lost.
For the record; Rich assigned specimen numbers to the fossils he placed in UGA’s paleontological collection, but no numbers are seen in the images he published so he either assigned numbers after creating the images or the numbers weren't physically on the specimens.
Parts of a Trilobite
Apparently, the finds were partial trilobites, as imaged in the original paper. I saw no mention of whole samples in Rich’s test, it’s always possible that I missed a phrase.
These are the basic parts of a trilobite.
Cephalon
Apparently, the finds were partial trilobites, as imaged in the original paper. I saw no mention of whole samples in Rich’s test, it’s always possible that I missed a phrase.
These are the basic parts of a trilobite.
Cephalon
- Head
- eyes, mouthparts, & antenna
- Midsection
- numerous articulated segments
- Tail
- fused segments
The holotype for the species is held at Harvard’s MCZ and is also a fragment of an individual. It’s a beautifully preserved cephalon (head) in a small slab. The fragment of an animals which lived more than 320 million years ago. No small thing.
I want to thank the staff of Harvard’s Museum of Comparative Zoology for taking these images at my request, especially Mark D. Renczkowski who took the photographs on 17/Feb/2025, previously there were no images in their online database. The pics show that the fossil is still safely held and in excellent condition.
Thanks Harvard MCZ!
- Javier Ortega-Hernández
- Associate Professor of Organismic and Evolutionary Biology
- Curator of Invertebrate Paleontology
- Jessica D. Cundiff
- Curatorial Associate
- Department of Invertebrate Paleontology
- Mark D. Renczkowski
- Curatorial Assistant (Photographer in this case.)
- Department of Invertebrate Paleontology
The images Renczkowski shared are largish files, too large for display on this page, so these have been reduced and credits have been added. The original size and format images are downloadable at the base of this page, as are Rich’s 1966 & 1973 papers.
UGA Specimens
An inquiry was sent to staff and faculty of the University of Georgia’s Department of Geology and the Georgia Natural History Museum on UGA’s campus, asking if the 1966 specimens were still held. Dr. Doug Crowe (Professor) and Dr. Sally Walker (Professor) replied to my question on 24/Feb/ 2025.
An inquiry was sent to staff and faculty of the University of Georgia’s Department of Geology and the Georgia Natural History Museum on UGA’s campus, asking if the 1966 specimens were still held. Dr. Doug Crowe (Professor) and Dr. Sally Walker (Professor) replied to my question on 24/Feb/ 2025.
Hi Thomas-
Mark Rich retired in 1990, one year prior to my arrival. At that point, the (Georgia Natural History Museum) museum was still 7 years from being formally recognized by the Georgia Legislature and was at best a loose assemblage of about a dozen faculty in multiple departments across campus who were actively involved in curating their own specific collections. Within Geology at that point, there were no faculty doing any sort of curation, such that there were several messy collections of teaching materials, but no organized research collections per se. Faculty would retire, put all their samples in cardboard boxes, which would then be placed in the damp basement in Barrow Hall. The typical lifespan of these boxes was about 5 years, at which point they had decomposed to the point that instead of a stack of boxes, there was a pile of rocks. As such, materials collected by many of our earliest faculty members (the department of Geology was officially established here at UGA in 1962) were simply lost. I began curating the Allard Economic Geology Collection in 1996, and in the process managed to also salvage mineralogy and petrology samples from faculty who had retired in those disciplines.
I cannot recall ever seeing any of Mark Richs’ materials at that point, so I have to assume that those were lost. That statement presumes, however, that Mark actually tried to curate and save them, which may not have been the case. Most faculty at that point simply dumped everything in our rockpile, and retired. There is not a formal “paleontological collection” in our department, Sally Walker does an awesome job with all her materials, but I don’t believe that effort includes salvaging much older material left behind by now passed on faculty. I’ve included her on this communication, perhaps she can add on to what I’ve said or correct me with regard to the materials you are interested in.
Regards,
Dr. Doug Crowe
Professor
UGA Geology
Mark Rich retired in 1990, one year prior to my arrival. At that point, the (Georgia Natural History Museum) museum was still 7 years from being formally recognized by the Georgia Legislature and was at best a loose assemblage of about a dozen faculty in multiple departments across campus who were actively involved in curating their own specific collections. Within Geology at that point, there were no faculty doing any sort of curation, such that there were several messy collections of teaching materials, but no organized research collections per se. Faculty would retire, put all their samples in cardboard boxes, which would then be placed in the damp basement in Barrow Hall. The typical lifespan of these boxes was about 5 years, at which point they had decomposed to the point that instead of a stack of boxes, there was a pile of rocks. As such, materials collected by many of our earliest faculty members (the department of Geology was officially established here at UGA in 1962) were simply lost. I began curating the Allard Economic Geology Collection in 1996, and in the process managed to also salvage mineralogy and petrology samples from faculty who had retired in those disciplines.
I cannot recall ever seeing any of Mark Richs’ materials at that point, so I have to assume that those were lost. That statement presumes, however, that Mark actually tried to curate and save them, which may not have been the case. Most faculty at that point simply dumped everything in our rockpile, and retired. There is not a formal “paleontological collection” in our department, Sally Walker does an awesome job with all her materials, but I don’t believe that effort includes salvaging much older material left behind by now passed on faculty. I’ve included her on this communication, perhaps she can add on to what I’ve said or correct me with regard to the materials you are interested in.
Regards,
Dr. Doug Crowe
Professor
UGA Geology
Greetings:
Mark Rich retired well before I got to UGA Geology. I have not encountered his specimens, even the foraminifera that he is known for (which would be on a lot of thin sections). However, the type samples for the papers you cited claim Harvard has the types, and that is very important. So, please enquire at Harvard’s MCZ to see if they do indeed have the types that you are looking for.
Sally (Walker)
Mark Rich retired well before I got to UGA Geology. I have not encountered his specimens, even the foraminifera that he is known for (which would be on a lot of thin sections). However, the type samples for the papers you cited claim Harvard has the types, and that is very important. So, please enquire at Harvard’s MCZ to see if they do indeed have the types that you are looking for.
Sally (Walker)
UGA Lost Fossils
Sadly, UGA has repeatedly lost scientifically important fossils. From both Mark Rich’s 1960’s research and Michael Voorhies 1970’s research, important specimens are just missing. Whether UGA’s Geology Department or Georgia Museum of Natural History, is ultimately responsible, I cannot say. The fact remains that irreplaceable fossils like Georgia’s first entelodont, perhaps the furthest south woolly mammoth in North America, new species of trilobites, the only fossils yet reported from the Piedmont…. All lost. It’s hard to justify this occurring at the best funded university in Georgia.
Sadly, UGA has repeatedly lost scientifically important fossils. From both Mark Rich’s 1960’s research and Michael Voorhies 1970’s research, important specimens are just missing. Whether UGA’s Geology Department or Georgia Museum of Natural History, is ultimately responsible, I cannot say. The fact remains that irreplaceable fossils like Georgia’s first entelodont, perhaps the furthest south woolly mammoth in North America, new species of trilobites, the only fossils yet reported from the Piedmont…. All lost. It’s hard to justify this occurring at the best funded university in Georgia.
In the last year I’ve been asked to support expanded funded for the Georgia Natural History Museum, but I find this hard to defend. My little website and related Facebook group is self, out-of-pocket, funded. I even applied for a little Earth Sci-Edu grant a few months ago and was turned down. Still, the website and Facebook group seems to have a wider reach and more Georgia natural history information than the Georgia Natural History Museum housed at the University of Georgia. It seems unlikely that additional funding will solve the recurring problem of lost fossils.
Horse teeth that Voorhies collected in Taylor County (1974) were borrowed, reviewed, and returned to UGA by Richard Hulbert at the Florida Museum of Natural in the 1980s, well after Voorhies left UGA. So the fossils were still somewhat organized and accessible then. Organized enough so that they could be found when Hulbert requested to review a specimen. These teeth helped date the creation of Taylor County’s peneplain, a significant geologic feature, now lost.
It's hard to justify this loss by the best funded university in Georgia. For more about lost historic UGA fossils see these pages of this website.
- https://www.georgiasfossils.com/14o-georgias-first-entelodont.html
- https://www.georgiasfossils.com/20i-pleistocene-vertebrate-fossils-on-georgiarsquos-piedmont.html
- https://www.georgiasfossils.com/19a-two-small-primitive-horses-from-taylor-county-advance-the-science-of-georgia-geology.html
- https://www.georgiasfossils.com/25f-collections--stewardship-of-georgiarsquos-fossils.html
Harvard
Thankfully, Havard University’s Museum of Comparative Zoology maintains online databases of its collections (a surprisingly rare thing for natural history museums) and Rich’s Australosutura georgiana is listed as held. No image of the fossils occurs in the record, though there is an image of the catalog entry when the fossil was accepted. I hope the image created for this website will be added to the database.
Thankfully, Havard University’s Museum of Comparative Zoology maintains online databases of its collections (a surprisingly rare thing for natural history museums) and Rich’s Australosutura georgiana is listed as held. No image of the fossils occurs in the record, though there is an image of the catalog entry when the fossil was accepted. I hope the image created for this website will be added to the database.
Their Curator of Invertebrate Paleontology, Javier Ortega-Hernández, kindly replied very favorably to my request. He expressed their desire to assist this website. He approved and passed my request on to Jessica Cundiff, their collections manager.
I’m so glad that Havard has preserved the specimen.
I’m so glad that Havard has preserved the specimen.
1976
In 1976 Rich published a second paper on the Lavender Shale covering additional fauna from the same locality including another genus of trilobite, Griffithides. He additionally reported the presence of bryozoans, echinoderms, brachiopods, and ostracodes in the Lavender Shale.
This report is worth look closely if new field trips are planned as Rich give detailed instructions on where they found specimens, but bear in mind his fieldwork was performed 50 years ago.
Rich reports additional flora & fauna
Genus Griffithides Trilobite
Genus Archaeocalamites Plant, horsetail relative
Confervites fasciculata Algae
In 1976 Rich published a second paper on the Lavender Shale covering additional fauna from the same locality including another genus of trilobite, Griffithides. He additionally reported the presence of bryozoans, echinoderms, brachiopods, and ostracodes in the Lavender Shale.
This report is worth look closely if new field trips are planned as Rich give detailed instructions on where they found specimens, but bear in mind his fieldwork was performed 50 years ago.
Rich reports additional flora & fauna
Genus Griffithides Trilobite
Genus Archaeocalamites Plant, horsetail relative
Confervites fasciculata Algae
Ryan Roney, Curator at Tellus Science Museum, has expressed interest in return to Rich’s research locales and seeing it his finds can still be duplicated. I wish Roney luck and look forward to hearing a report on his exploration.
Science is a journey, not a destination.
Science is a journey, not a destination.
Original Format & Size Images Below
| mcz110939_australosutra_georgiana_1__2_.jpg |
| mcz110939_australosutra_georgiana_2.jpg |
Rich's Original Papers
| rich_1966-mississippiantrilobitesnorthwestern__2_.pdf |
| rich_1973-earlymississippianplant-.pdf |
References
- Rich, Mark; Mississippian trilobites from Northwestern Georgia, Journal of Paleontology, V.40, No. 6, Pgs 1381-1384, November 1966
- Rich, Mark; Early Mississippian Plant & Trilobite Remains From Northwestern Georgia, Journal of Paleontology, V.47, No. 6, November 1973