Left ulna, radius and hand of Megalonyx jeffersonii.
33 inches long with 13 inch hand width
Megalonyx jeffersonii
Jefferson Ground Sloth
West Virginia State Fossil
President, Thomas Jefferson, scientifically described fossil bones given to him by saltpeter miners found in a Monroe County cave in 1797. Jefferson thought they were the claws of a giant cat. In 1799 Casper Wistar re-described the bones as a new species of extinct giant ground sloth and named it in honor of President Jefferson. Only recently have the bones been Carbon 14 dated at over 38,000 year old.
Megalonyx jeffersonii became the official State Fossil of West Virginia in March, 2008