11" Fossil Tortoise (Stylemys) with Visible Limb Bone - Wyoming

Fossil Tortoise (Stylemys) with Visible Limb Bone - Wyoming #281492

This is a beautiful, 11" tortoise (Stylemys nebrascensis) shell from the White River Formation in Wyoming. Both the carapace and the plastron are present, along with an exposed limb bone (femur) 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.

Many of the marginal scutes along the anterior and posterior edges of the carapace are either completely or partially restored. The central scutes at the posterior end of the shell are also restored. The anterior most scutes along the plastron have undergone some restoration. In total, restoration makes up approximately 5% of the 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.

SPECIES

Stylemys nebrascensis

AGE

Middle Oligocene