''Stylemys'' (meaning "pillar turtle") is the first

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

genus of dry land

tortoise Tortoises ( ) are reptiles of the family Testudinidae of the order Testudines (Latin for "tortoise"). Like other turtles, tortoises have a shell to protect from predation and other threats. The shell in tortoises is generally hard, and like o ...

belonging to the order

Testudines Turtles are reptiles of the order (biology), order Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Crypt ...

discovered in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. The genus lived in temperate to subtropical areas of North America,

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

, and Asia, based on fossil distribution. The genus was first described in 1851 by Joseph Leidy. The tortoise was common in the prehistoric Badlands, especially Nebraska and South Dakota. The species has also been found in the formations in and around Badlands National Park. Fossil fragments have also been found in the Palm Park Formation of New Mexico. The ancient tortoises had primitive jaw muscles, unlike today's tortoises, which also display the ''os transiliens'' bone, and would have been herbivorous. While ''Stylemys'' species did exhibit the same neck structure as modern tortoises, the forelimbs were unsuitable for burrowing, setting them apart from modern genera.

Species

A number of species have been described since the genus was named in 1851.The Paleobiology Database
/ref>

Time period

Eon: Phanerozoic Era: Cenozoic Period: Paleogene Epoch: Eocene *''S. botti'' *''S. calaverensis'' *''S. canetotiana'' *''S. capax'' *''S. conspecta'' *''S. copei'' *''S. emiliae'' *''S. frizaciana'' *''S. karakolensis'' *''S. nebrascensis'' (syn. ''S. amphithorax'') *''S. neglectus'' *''S. oregonensis'' *''S. pygmea'' *''S. uintensis'' *''S. undabuna'' Image:Stylemys_conspecta_01.jpg, ''Stylemys conspecta'' from Tertiary period, Tertiary in Oregon Image:Stylemys.jpg, ''Stylemys nebrascensis'' shell at the Museum für Naturkunde, Berlin

References

* * * https://web.archive.org/web/20080521150612/http://cumuseum.colorado.edu/Research/Objects/jun06_tortoise.html * http://www.paleoclones.com/item.php?item=929
nps.gov
Testudinidae Cenozoic turtles of North America White River Fauna Prehistoric turtle genera Taxa named by Joseph Leidy Extinct turtles {{paleo-turtle-stub