Merychippus

merychippus
Merychippus (Wikimedia Commons).

Name:

Merychippus (Greek for "ruminant horse"); pronounced MEH-ree-CHIP-us

Habitat:

Plains of North America

Historical Epoch:

Late Miocene (17-10 million years ago)

Size and Weight:

About three feet tall at the shoulder and up to 500 pounds

Diet:

Plants

Distinguishing Characteristics:

Large size; recognizably horse-like head; teeth adapted to grazing; vestigial side toes on front and hind feet

 

About Merychippus

Merychippus was something of a watershed in equine evolution: this was the first prehistoric horse to bear a marked resemblance to modern horses, although it was slightly bigger (up to three feet high at the shoulder and 500 pounds) and still possessed vestigial toes on either side of its feet (these toes didn't reach all the way to the ground, though, so Merychippus still would have run in a recognizably horselike way).  By the way, the name of this genus, Greek for "ruminant horse," is a bit of a mistake; true ruminants have extra stomachs and chew cuds, like cows, and Merychippus was in fact the first true grazing horse, subsisting on the widespread grasses of its North American habitat.

The end of the Miocene epoch, about 10 million years ago, marked what paleontologists call the "Merychippine radiation": various populations of Merychippus spawned about 20 separate species of late Cenozoic horses, distributed across various genera, including Hipparion, Hippidion and Protohippus, all of these ultimately leading to the modern horse genus Equus. As such, Merychippus probably deserves to be better known than it is today, rather than being considered just one of the innumerable "-hippus" genera that populated late Cenozoic North America!