California crews working on an infrastructure project were surprised this month when they uncovered the fossilized bones of a large, hoofed mammal that walked the region’s ancient floodplains over 40 million years ago.
The bones include several ribs, a femur and other limb bones and fragments that could have belonged to a brontothere, which is also known as a “thunder beast,” according to paleontologist Dr. Joseph El Adli, who made the discovery during routine monitoring of the a City of Oceanside project.
