Macraucheniidae

From Wikipedia, the free encyclopedia

You have new messages (last change).

Macraucheniidae

An artist's impression of a Macrauchenia herd grazing.

Conservation status

Extinct (fossil)

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Litopterna
Family:	Macraucheniidae Gill, 1872

Macraucheniidae is a family in the Litopterna order. The recessed nasal bones of their skulls suggest that they may have had a small proboscis, or trunk. Their hooves were similar to those of rhinoceroses today, with a simple ankle joint and three digits on each foot. Thus, they may have been capable of rapid directional change when running away from predators, such as large Phorusrhacos terror birds and Smilodon saber-toothed cats. Macraucheniids probably lived in large herds to gain protection against these predators, as well as to facilitate finding mates for reproduction.

The family Macraucheniidae includes genera such as Theosodon, Xenorhinotherium, and Macrauchenia. Macrauchenia is the best-known and most recent macraucheniid. It became extinct during the Pleistocene Epoch. This was probably due to the ecological pressures of the Great American Interchange between North and South America, which took place after the Isthmus of Panama rose above sea level some 3 million years ago. When Macrauchenia died out, so too did the Macraucheniidae and the entire litoptern order.