Megalonyx
Megalonyx (Greek, "great-claw") is an extinct genus of ground sloths of the family Megalonychidae, native to North America. It evolved during the Pliocene Epoch and became extinct during the Quaternary extinction event at the end of the Late Pleistocene-Early Holocene, living from ~5 million to ~13,000 years ago. The type species, M. jeffersonii (also called Jefferson's ground sloth), the youngest and largest known species, measured about 3 meters (9.8 ft) in length and weighed up to 1,000 kilograms (2,200 lb).
| Megalonyx | |
|---|---|
| M. wheatleyi skeleton in AMNH | |
| Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Pilosa |
| Family: | †Megalonychidae |
| Subfamily: | †Megalonychinae |
| Genus: | †Megalonyx Disputed, see text |
| Type species | |
| †Megalonyx jeffersonii Desmarest 1822 | |
| Species | |
Megalonyx was descended from Pliometanastes, a genus of ground sloth that had arrived in North America during the Late Miocene around 9 million years ago, prior to the main phase of the Great American Interchange. Megalonyx had the widest distribution of any North American ground sloth, having a range encompassing most of the contiguous United States, extending as far north as Alaska during warm periods.