For over fifty years, a prehistoric rhinoceros mass grave has baffled paleontologists. Over one hundred rhino skeletons were found in the same spot, having all died together 12 million years ago. Now, a new study has revealed that this mass of animals, which died together, also lived together in one huge herd. How do we know? Their teeth.
Rhinos buried in ash
Located about 160 km from Sioux City, Iowa, the Ashfall Fossil Beds were created by the Yellowstone volcanic eruption 11.9 million years ago. When the volcano blew, a dense blanket of ash covered the entire region. Smaller animals died almost instantly, suffocating on the abrasive ash.
For larger, hardier creatures like the Teleoceras major, the barrel-bellied rhino, it was slower. Volcanic ash, on a microscopic level, is actually quite sharp, like tiny shards of glass. As it filled their lungs, animals slowly sickened and died. They came to the watering hole, seeking some relief in the cool water. There they died, and the wind swept more ash on top of them. What had killed them also preserved them perfectly.
In 1971, Michael and Jane Voorhies were walking down gullies in Northwestern Nebraska. Michael was a University of Nebraska State Museum paleontologist who hoped that erosion by nearby Verdigre Creek had revealed fossils…