Nothrotheriops

Nothrotheriops is an extinct genus of ground sloths endemic to North America during the Pleistocene to early Holocene (~2.5 Mya until 10,000 years ago). The genus contains two species, N. shastensis and N. texanus, the former of which is also known as the Shasta ground sloth.

==Taxonomy, history, and etymology== thumb|left|N. shastensis skull Nothrotheriops fossils were first collected by the University of California's Anthropology Department during an exploration of caves at Potter Creek Cave in Shasta County, California, the fossils dating to the late Quaternary period. These first fossils (UCMP 8422), consisting of an incomplete mandibular ramus lacking teeth of an individual and 14 additional molars, were sent to the University of California Museum of Paleontology, where they were described by paleontologist William Sinclair in 1904 as a new species of Nothrotherium, N. shastensis (species name meaning "from Shasta"). In 1916, Smithsonian paleontologist Oliver P. Hay named Nothrotherium texanus (species name meaning "from Texas") based on a partial skull that was transferred from Baylor University in Waco, Texas. The skull had been collected in the Pleistocene strata of Wheeler County, Texas, and given to a clergyman, who then gave it to university staff in 1901. Many fossils were later referred to the two, but N. shastensis was not placed in a new genus until 1954, when it was placed in a new genus, Nothrotheriops ("near slothful beast", due to its similarity to Nothrotherium) by Robert Hoffstetter during a study of fossil sloths. N. texanus was recombined into the genus in 1995, and had many fossils referred to it from Florida, the easternmost occurrence of the genus.