noun
A ground sloth of the genus Megalonyx (family Megalonychidae), known from fossil remains found in Pliocene and Pleistocene deposits in North America.
Origin
Late 18th century; earliest use found in Thomas Jefferson (1743–1826), revolutionary politician and president of the United States of America. From scientific Latin Megalonyx, genus name from ancient Greek μεγαλο- + ὄνυξ claw.
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