10" Fossil Tortoise (Stylemys) with Visible Limb Bones - Wyoming

Fossil Tortoise (Stylemys) with Visible Limb Bones - Wyoming #280872

This is a beautiful, 10" tortoise (Stylemys nebrascensis) shell from the White River Formation in Wyoming. Both the carapace and the plastron are present, along with exposed limb bones within the rock. It is well inflated, in good condition and largely intact. Many of the tortoises from this formation are quite compressed, so this specimen is really something special.

For a shell of this size it has fairly excellent preservation. It was pulled out from the ground in two pieces, hence the repaired crack with gap fill running through the middle of the specimen. While the scutes are somewhat separated, restoration is very minimal as most of the gaps are filled with natural rock.

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.

SPECIES

Stylemys nebrascensis

AGE

Middle Oligocene