Nothrotheriops is a genus of Pleistocene ground sloth found in North America, from what is now central Mexico to the southern United States. This genus of bear-sized xenarthran was related to the much larger, and far more famous Megatherium, although it has recently been placed in a different family, Nothrotheriidae. The best known species, N. shastensis, is also called the Shasta ground sloth.
Image: Shasta ground sloth front
Image: Nothrotheriops shastensis
N. shastensis skull
Holotype skull of N. texanus.
Ground sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. Ground sloths varied widely in size, with the largest, belonging to genera Megatherium and Eremotherium, being around the size of elephants. Ground sloths are a paraphyletic group, as living tree sloths are thought to have evolved from ground sloth ancestors.
Ground sloth
Fossil Eremotherium skeleton, National Museum of Natural History, Washington, DC.
Paramylodon harlani, Texas Memorial Museum, University of Texas at Austin
A Tamandua anteater in an upright defensive stance similar to those presumed to have been adopted by ground sloths, per trackways preserved in New Mexico
