A stunning fossil was found in the 2016 season. Ashfall Fossil Beds summer intern Mikayla Struble (Montana State University) was conducting work in the Hubbard Rhino Barn when she uncovered the skull of a three-toed horse skeleton identified as Pseudhipparion gratum.
“There was a very good chance that this was not a skeleton - just an isolated skull, but the excavation has progressed to where it is apparent that it is a quite complete skeleton” said Rick Otto, Park Superintendent.
Not much bigger than a large dog, Pseudhipparion is the smallest of the Ashfall horses. It is also the most abundant with remains of more than 50 individuals, from newborns to old adults, that have been excavated at the site to date.
“At first, I thought it might be a pelvis,” Struble reports. “But after exposing more, I was excited to realize it was a skull.”
Pseudhipparion originated about 14 million years ago and became extinct 10 million years ago, generally becoming smaller in body size throughout this time range, differing from most horse lineages in this respect.
The skeleton is located several feet from the viewing deck and presents visitors with an optimal viewpoint as excavation continues.