Abstract:
There are two fossil species of Plesiogulo in North America: Plesiogulo marshalli, to which most of the fossil material is herein referred, and P. lindsayi, new species. Both species are restricted to the late Hemphillian. A formal diagnosis is offered for P. marshalli. Remains of Plesiogulo are relatively rare, possibly due to low densities in extinct populations. The only known juvenile specimens of Plesiogulo are from the Edson Local Fauna, where three juveniles together with a single mature individual probably represent a female with a litter of cubs. Plesiogulo migrated to the New World some time between 7.0 and 6.5 million years ago. This taxon, generally interpreted as an inhabitant of forest or woodland, was probably equally well adapted to the open plains.
