American Zebra; also known as the Hagerman horse and Equus simplicidens
Plains of North America
Pliocene (5-2 million years ago)
Size and Weight:
About 4-5 feet tall and 500-1,000 pounds
Stocky build; narrow skull; probably stripes
About the American Zebra:
When its remains were first unearthed, in 1928, the American Zebra was identified as a new genus of prehistoric horse, Plesippus. On further examination, though, paleontologists determined that this stocky, thick-necked grazer was one of the earliest species of Equus, the genus that comprises modern horses, zebras and donkeys, and was most closely related to the still extant Grevy's Zebra of eastern Africa. Also known as the Hagerman horse (after the town in Idaho where it was discovered), Equus simplicidens may or may not have sported zebra-like stripes, and if so, they were probably restricted to limited portions of its body. Notably, this early horse is represented in the fossil record by no less than five complete skeletons and a hundred skulls, the remnants of a herd that drowned in a flash flood about three million years ago.