Temporal range: Late Miocene – Pleistocene
Megalonyx jeffersonii by tuxemperor-d98s9tv.png
An artist's illustration of Megalonyx jeffersonii
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Superorder: Xenarthra
Order: Pilosa
Family: Megalonychidae
Subfamily: Megalonychinae
Genus: Megalonyx
Harlan, 1825
Type species
Megalonyx jeffersonii
Desmarest, 1822
Referred species
  • Megalonyx jeffersonii
    (Desmarest, 1822) (type)
  • Megalonyx leptostomus
    (Cope, 1893)
  • Megatherium matthisi
    (Hirschfeld & Webb, 1963)
  • Megatherium wheatleyi
    (Cope, 1871)

Megalonyx (meaning "large claw"), also known as the Jefferson's ground sloth, was a genus of ground sloths of the family Megalonychidae endemic to North America from the Hemphillian of the Late Miocene through to the Rancholabrean of the Pleistocene, living from ~10.3 million years ago — 11,000 years ago, existing for approximately 10.289 million years. Type species, Megalonyx jeffersonii, measured about 3 m (9.8 ft) and weighed up to 1,000 kilograms.

In popular culture

  • Megalonyx appeared in the documentary Before We Ruled The Earth.


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