In the new work, the authors studied the teeth and bones of the lower jaw of 29 ancient ungulates, or condylar, from the Early Paleocene deposits. They used phylogenetic methods to understand the anatomical differences between species, and also established how these species relate to each other and to other Paleocene condilarra in North America.
As a result, it became known about three new species of ancient mammals, they were named:
- Miniconus jeanninae,
- Conacodon hettingeri,
- Beornus honeyi.
All three species belong to the family of periptychids – these are extinct placentals. The largest representative was the size of a modern domestic cat, but mammals were even smaller in the days of the dinosaurs. This suggests that their extinction made it possible for mammals to develop.
When dinosaurs became extinct, access to food and other environmental resources allowed mammals to develop rapidly, diversify anatomy, and increase body size. They clearly seized the opportunity, as we can see from the diversity of new mammalian species that arose in a relatively short time after the mass extinction.
Madeleine Atteberry, lead author of the study
According to the authors of the new work, mammals were omnivores, so they had teeth that can be used to grind both plant and animal food.