5.5" Red, Fossil Tortoise (Stylemys) - South Dakota

Red, Fossil Tortoise (Stylemys) - South Dakota #227350

This is a red, 5.5" long fossil tortoise (Stylemys nebrascensis) from the White River Formation in South Dakota. It has been prepared to leave it on the mudstone on which is was found, and it has no restoration. A pretty unusual specimen.

Stylemys ("pillar turtle") is the first fossil genus of dry land tortoise discovered in the United States. They lived in temperate to subtropical areas of North America, Europe, and Asia.

These extinct tortoises had primitive jaw muscles, unlike today's tortoises that 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 weren't ideal for burrowing.