11.8" Colorful, Inflated Fossil Tortoise (Stylemys) - South Dakota

Colorful, Inflated Fossil Tortoise (Stylemys) - South Dakota #280686

This is a massive, 11.8" long shell (carapace and plastron) of an Oligocene-aged tortoise (Stylemys nebrascensis) from the White River Formation in the Badlands of South Dakota. It is nicely inflated with minimal crushing and gorgeous red-orange preservation. A partial limb bone can be seen exposed from the rock.

This huge specimen weighs in at a whopping 28.6 lbs!

The shell is 98% complete. There are some repaired cracks between scutes requiring minor gap fill, and the edges of a couple of the marginal scutes have spots of restoration.

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.