Fossil Turtles of South Dakota

1. Fossil Turtles of South Dakota Lilly Sanovia Oglala Lakota College June, 2012

2. The Oligocene Epoch • 34-24 million years ago • Begins with a major extinction event • The climate was cooling after a warm, tropical period during the Eocene • Considered a major transition period from ancient to more modern species • Transition of the Great Plains from a closed, subtropical forest to a drier grassland

3. Oligocene Fauna of the Great Plains • Entelodonts (peccaries) • Camels • Running rhinos • Mesohippus (three-toed horses) • Nimravids (false saber-tooth cats) • Protoceratids (even-toed herbivores) • Hesperocyon (early dogs) • Oreodonts (cattle-sized ruminating hogs)

4. The White River Group • Formed during the late Eocene through the Oligocene (37-27 mya) • Turtles are the most common vertebrate fossil found in White River Group rocks • Units: • Chadron Formation (Chadronian Land Mammal Age) • Brule Formation (Scenic and Poleside members – Orella and Whitneyan Land Mammal Ages) • Many fossil turtles found in the Brule Formation • Sharps Formation (Arikareean Land Mammal Age)

5. White River Group Distribution Source: Tephrostratigraphy and Source of the Tuffs of the White River Sequence, Larson and Evanoff, 1998

6. White River Group Genera • Five genera of turtles are found in White River Group Formations: • Geochelone • Gopherus • Hesperotestudo • Stylemys • Testudo

7. Identifying Fossil Genera • A number of features have been used in the past to identify fossil tortoises • Sutures • Borders between costals and peripherals • Nuchal size and shape • Neural shape • Peripheral bridge pits

8. Challenges in Identifying Genera Many of these characteristics are of questionable diagnostic value as they can vary with: • Size of the fossil • Completeness of the fossil • Age of the animal when fossilized • Criteria that are highly subjective • Overlap of characteristics between species • Skill set and training of the scientist

9. Generalized Features Generalized testudine carapace (A, C) and plastron (B, D) (from Zangerl, 1969). Source: Reassessment of Characteristics Determining Generic Affinity in Gopherus AND Stylemys (Testudinidae) from the White River Group, Badlands National Park, William P. Wall and Dennis Maddox

10. Fossil Land Turtles • No teeth, as in modern tortoises • From this we can infer a diet of low growing shrubs, grasses, cacti and insects • Had modified jaw muscles that allowed the head to retract into the carapace • Many fossil carapaces have been found overturned and in pieces, many with missing body parts (limbs, tail) • Do we infer predation from this?

11. Stylemys Classification Kingdom: Animalia Phylum: Chordata Class: Reptilia Superorder: Chelonia Order: Testudines Family: Testudinidae Genus: Stylemys Leidy, 1851 Fossil Stylemyscapaxcarapce Source: Wikipedia

12. Stylemys Species • S. botti • S. calaverensis • S. canetotiana • S. capax • S. conspecta • S. copei • S. emilliae • S. frizaciana • S. karakolensis • S. nebrascensis • S. neglectus • S. oregonensis • S. pygmea • S. uintensis • S. undabuna

13. Gopherus Classification Kingdom: Animalia Phylum: Chordata Class: Reptilia Order: Testudines Suborder: Cryptodira Superfamily: Testudinoidea Family: Testudinae Genus: Gopherus Daudin, 1802 Desert or gopher tortoise Burrows Living descendants even today Source: Wikipedia Some think Stylemys belongs in the Gopherus genus

14. Geochelone • Kingdom: Animalia • Phylum: Chordata • Class: Sauropsida • Order: Testudines • Suborder: Cryptodira • Family: Testudinidae • Genus: Geochelone • Fitzinger, 1835 • Giant land tortoises, now extinct • Some descendants exist today in Asia and South America

15. Testudo • 5 species described by Dr. Joseph Leidy in “The Ancient Fauna of Nebraska” (1851) • Testudonebrascensis (now Stylemysnebrascensis) • Testudohemispherica • Testudooweni • Testudoculbertsonii • Testudolata Source: The Ancient Fauna of Nebraska, Dr. Joseph Leidy, 1851

16. Hesperotestudo Kingdom: Animalia Phylum: Chordata Class: Sauropsida Order: Testudines Suborder: Cryptodira Superfamily: Testudinoidea Family: Testudinae Genus: Hesperotestudo Williams, 1950 Giant land tortoises Extinct – lived from the Miocene to the Pleistocene Source: Ashfall Fossil Beds State Historical Park, Orchard, NE

17. Stan’s Carapace Collected on private land adjacent to the Badlands in the 1960s Tentatively identified as Stylemysnebrascensis Measurements: 17 inches across the widest part (from peripheral to peripheral) 16 inches in length. Nuchals and head are not present.

18. Stan’s Plastron Measurements: 11 inches across at the widest point with a maximum length of 8 inches and minimum length of 5 inches. Held together by coarse sandy sediment and glue

19. Rare Earth Element Analysis of Fossils • Rare Earth Element (REE) analysis of fossils is made possible due to the presence of apatite in fossilized bone • There is uptake of trace elements from pore waters by the apatite in fossilized bone • Analysis of these trace elements gives us information about the environment during the time that the fossilized animal was alive. • Analysis can also provide valuable information in reconstruction of the faunal assemblages present during a certain period or within a certain stratigraphic layer • REE analysis can be used to correctly assign a fossil to the stratigraphic layer from which it came (with ~90% accuracy) • This is especially useful for fossils which were collected without location data or stratigraphic information

20. REE Analysis by X-Ray Fluorescence • REE analysis is accomplished by x-ray fluorescence and/or inductively coupled plasma mass spectrometry • We have an x-ray fluorescence machine in the laboratory of the Math and Science building at PiyaWiconi • I propose to undertake an REE analysis by x-ray fluorescence of Stan’s carapace to help determine which stratigraphic unit this animal was fossilized in. • This will provide information useful to identifying the genera of this specimen. • REE analysis by x-ray fluorescence could be carried out on other specimens in the fossil collection at PiyaWiconi as an aid to reconstructing the paleoenvironment in the study area.

21. Acknowledgements • Dr. Hannan LaGarry • Oglala Lakota College, Math and Science Department • South Dakota School of Mines and Technology, Museum of Geology

22. Literature Cited • Bump, J.D. "Geographic Names for Members of the Brule Formation of the Big Badlands of South Dakota." American Journal of Science 254 (1956): 429-32. Print. • Clark, J. "The Stratigraphy and Paleontology of the Chadron Formation in the Big Badlands of South Dakota." Carnegie Museum Annals 25 (1937): 261-350. Print. • Clark, J. "Geographic Designation of the Members of the Chadron Formation in South Dakota." Carnegie Museum Annals 33 (1954): 197-98. Print. • Clark, J., J.R. Beerbower, and K.K. Kietzke. "Oligocene Sedimentation, Stratigraphy, Paleoecology, and Paleoclimatology in the Big Badlands of South Dakota." Fieldiana Geology Memoirs 5 (1967). Print. • "Cretaceous-Tertiary Boundary Interval in Badlands National Park, South." Docstoc – Documents, Templates, Forms, Ebooks, Papers & Presentations. Web. 31 July 2011. http://www.docstoc.com/docs/51476311/Cretaceous-Tertiary-Boundary-Interval-in-Badlands-National-Park-South • Evans, James E., and Linda C. Welzenbach. "Episodes of Carbonate Deposition in a Siliciclastic-dominated Fluvial Sequence, Eocene-Oligocene White River Group, South Dakota and Nebraska." Geological Society of America Special Paper 325 (1998). Print. • Jones, Lilly. “Current Understanding of the White River Group” (2011), Oglala Lakota College, Junior Research. Unpublished. • LaGarry, Hannan E. "Lithostratigraphic Revision and Redescription of the Brule Formation (White River Group) of Northwestern Nebraska." Geological Society of America Special Paper 325 (1998). Print. • Larson, Edwin E., and Emmett Evanoff. "Tephrostratigraphy and Source of the Tuffs of the White River Sequence." Geological Society of America Special Paper 325 (1998). Print. • Leidy, Joseph, “The Ancient Fauna of Nebraska” (1851): http://www.archive.org/stream/ancientfaunaofne00leid#page/n7/mode/2up (Accessed 11/26/11), Library, U.S. National Museum, Smithsonian Institution. Print. • Prothero, Donald R., Charles R. Denham, and Harlow G. Farmer. "Oligocene Calibration of the Magnetic Polarity Time Scale." Geology 10.12 (1982): 650. Print. • Prothero, D.R., and C.C., III Swisher. "Magnetostratigraphy and Geochronology of the Terrestrial Eocene-Oligocene Transition in North America." Eocene-Oligocene Climatic and Biotic Evolution (1992), Princeton New Jersey, Princeton University Press: 46-73. Print.

23. Literature Cited • Retallack, Gregory J. "Late Eocene and Oligocene Paleosols from Badlands National Park, South Dakota." Geological Society of America Special Paper 193 (1983). Print. • Retallack, Gregory J. "Neogene Expansion of the North American Prairie." PALAIOS 12.4 (1997): 380-90. Print. • Terry, Jr., Dennis O., and James E. Evans. "Pedogenesis and Paleoclimatic Implications of the Chamberlain Pass Formation, Basal White River Group, Badlands of South Dakota." Palaeogeography, Palaeoclimatology, Palaeoecology 110 (1994): 197-215. Print. • Terry, Jr., Dennis O., Hannan E. LaGarry, and W. Brantly Wells. "The White River Group Revisited: Vertebrate Trackways/ Ecosystems, and Lithostratigraphic Revision, Redefinition and Redescription." Geologic Field Trips in Nebraska and Adjacent Parts of Kansas and South Dakota 10th ser. (1995): 43-58. Print. • Terry, Jr., Dennis O., and Hannan E. LaGarry. "The Big Cottonwood Creek Member: a New Member of the Chadron." Geological Society of America Special Paper 325 (1998). Print. • Terry, Jr., Dennis O. "Lithostratigraphic Revision and Correlation of the Lower Part of the White River Group: South Dakota to Nebraska." Geological Society of America Special Paper 325 (1998). Print. • Terry, Jr., Dennis O., John A. Chamberlain, Philip W. Stoffer, Paula Messina, and Patricia A. Jannett. "Marine Cretaceous-Tertiary Boundary Section in Southwestern South Dakota." Geology 29.11 (2001): 1055. Print. • The Fossils of the White River Badlands: http://whiteriver.weebly.com/tortoises.html, Accessed 11/22/2011 • Trueman, C.N., Behrensmeyer, A.K., Potts, R. Tuross, N. “High-Resolution records of location and stratigraphic provenance from the rare earth element commposition of fossil bones.” Geochimica et CosmochimicaActa. Volume 70, Issue 17. (1 September 2006). Pages 4343-4355. Print. • Wall, William P., and Maddox, Dennis. “Reassessment of Characteristics Determining Generic Affinity in Gopherus AND Stylemys (Testudinidae) from the White River Group, Badlands National Park.” Paleontological Research, Volume III (October, 1998), National Park Service. Print.