Hyaenodon horridus

Hyaenodon horridus  (Hyaenodon Leidy, 1869)

Class: Mammalia

Order: Creodonta

Family: †Hyaenodontidae

Time period:  late Eocene and early Oligocene (North America)

Size: Up to‭ 1,8‭ ‬meters long. 80 ‬cm tall at the shoulder.  Weight estimated at up to‭ 50‭ ‬kg.

Hyaenodon horridus ("hyaena-toothed") is an extinct genus of Hyaenodonts, a group of carnivorous creodonts of the family Hyaenodontidae endemic to all continents except South America, Australia and Antarctica, living from 42-15.9 mya, existing for approximately 26.1 million years. The average weight of adult or sub-adult Hyaenodon horridus, the largest North American species, is estimated to be about 40 kg  and may not have exceeded 60 kg.