Oligocene Tortoise Stylemys
Stylemys nebrascensis
Brule Formation
Middle Oligocene
Niobrara County, Wyoming
Here is a perfect Stylemys from our collection that is museum quality. This outstanding example shows excellent detail and has almost no distortion. Both carapace and plastron are complete and there is no restoration. The shell detail is excellent and would be a top-rate addition to any serious White River collection. This specimen is better that any seen in most museums.

Stylemys (meaning pillar turtle) is the first fossil genus of dry land tortoise belonging to the order Testudines discovered in the United States. The genus lived in temperate to subtropical areas of North America, Europe, and Asia, based on fossil distribution. The genus was first described in 1851 by Dr. Joseph Leidy. The tortoise was common in the prehistoric Badlands, especially Nebraska and South Dakota. Stylemys is found throughout the White River Group from Chadronian through Whitneyan age. It also occurs in Oregon, California, Utah, Texas, Wyoming, and Colorado. Few Badlands fossils are more abundant, widely distributed, or better preserved than this genera. The shell body is often preserved with remarkable perfection, but upon exposure by erosion, they disintegrate quickly. Associated bones and skulls are rarely found. Fossil tortoise eggs of this genus have also been found in the host formation.