Name Meaning: Ruminating Tooth
Geologic Era: Late Eocene to Early Miocene (specimen is from the Oligocene)
Location Discovered: White River Formation, Nebraska
Size: 1.4 meters long (sheep size)
Estimated Range: Canada to Florida
Extinction Date: Early Miocene (about 16 million years ago)
This is most of the left side of a Merycoidodon culbertosoni skull. The end of the snout is missing, but most of thee rest of the skull is intact. The skull half is mounted in a plaster base for ease of display. Oreodont remains like Merycoidodon are very common in the White River formation. This is also the specimen that is on the front page of the museum.
Given how common Merycoidodon (and oreodont remains in general) are, it must have been a very common animal in its environment. A fair analogy in modern ecosystems might be large herds of deer or caribou in Northern latitudes, or zebras in Africa. Given how many mass burials of Merycoidodon that have been found, it is likely that they traveled in herds, or at the very least family groups. There is also evidence of scent glands in Merycoidodon’s skull, similar to what modern deer have. This means that individuals and herds were probably at least somewhat territorial.
The way Merycoidodon’s feet and legs were structured suggest that it was not a terribly fast moving animal, and probably relied on safety in numbers where predators were concerned. Given how common Merycoidodon was in its environment, it was certainly a prey animal for a respectable number of predators, including Dinictis (a nimravid cat), Hyeanodon, and Archaeotherium. Merycoidodon remains tend to be found in areas that were once watering holes or rivers. If that was the case, all a predator would have to do is wait by one of these areas, and the Merycoidodon would come to it.
Full Skeleton: https://commons.wikimedia.org/w/index.php?curid=19862194