7.1" Fossil Running Rhino (Hyracodon) Upper Jaws - South Dakota

Fossil Running Rhino (Hyracodon) Upper Jaws - South Dakota #232225

This is a beautiful, 7.1" long partial upper skull of Hyracodon sp. ("running rhino"). It was collected from the Brule Formation in Pennington County, South Dakota, and would be approximately 30-34 million years old. The specimen features a partial upper skull still incased in rock, with the teeth exposed facing upward.

The base of the rock has been cut flat beneath the molars, allowing it to sit nicely on a flat surface. The teeth on one side of the jaw are broken/damaged, while the remaining teeth are in pristine condition.

Hyracodons were hornless running rhinoceroses with large heads compared to their slight, pony-like bodies. They are an extinct line, though: we're sure you've noticed that there are no rhinos browsing the plains of North America today.