Megalonyx–Mega What?

Megalonyx jeffersoni is an extinct giant ground sloth, whose bones were first found in a West Virginia cave and shown to Thomas Jefferson. Jefferson, who had previously been embroiled in a debate with the French naturalist the Comte de Buffon about the “degeneracy” of American fauna, was always excited to find examples of massive American animals that proved the equality (or superiority) of the New World as compared with the Old. In March of 1797 Jefferson gave a talk at the American Philosophical Society on the sloth, which he named megalonyx or “great claw.” Jefferson even hoped that the sloth might still be extant somewhere in the American wilds and he remarked in a letter that he thought it possible that Lewis and Clark’s expedition might find some.

You can find out more about Jefferson’s sloth at the Academy of Natural Sciences website and of course in our upcoming exhibition, which will feature bones on loan from the Academy alongside our own Buffon encyclopedia.

As a preview, here’s a 1799 engraving of the bones which Jefferson saw.

Wistar, Caspar. 1799. “A description of the Bones deposited by the President, in the Museum of the Society, and represented in the annexed plates.” Transactions of the American Philosophical Society, Vol. 4, No. 71, pp. 526-531.

Here’s a more complete mounted reconstruction at the Ohio State University Museum

And just for kicks, here’s Rusty, a model Megalonyx at the University of Iowa Museum of Natural History.

You can see more pictures of Rusty decked out for every season on his very own Facebook page!

Lions and tigers and sloths, oh my!