Photo: National Park Service, Fossil Butte National Monument
- Order
- Pantolesta
- Family
- Pantolestidae
An otter-like swimmer known from three nearshore skeletons — one with fish in the stomach.
Three skeletons of this species have been discovered from nearshore deposits of the FBM, one with fish bones and scales preserved in the stomach. It had strong pectoral muscles adapted for swimming. The large, strong feet and tail are similar to those found on modern otters.
However, P. didelphoides and modern otters are not related and arise from separate lineages — an example of convergent evolution, where species of different lineages develop similar traits from living in similar environments and occupying similar ecological niches.
Species text: National Park Service, Fossil Butte National Monument — Fossil Mammal Species.