Oligocene Oddities

In a departure from dinosaurs in color, here are some sketches I did last winter of North America's Oligocene mammals:

Archaeotherium, an early member of the entelodonts (a.k.a. the "terminator pigs", though they're now believed to been more closely related to hippos and whales.

Miohippus, an early horse.

Subhyracodon, an early, hornless rhinoceros. This cow-sized herbivore lived at about the same time as the indricotheres, hornless rhinos that grow taller than giraffes and heavier than the largest elephants.