Megalonyx jeffersoni, ground sloth juvenile skull, Now The West Virginia State Fossil Triceratops Many fossils of this species

Many fossils of this species

and a tail shield (pygidium)

was found in the Fossil Butte Member of the Green River Formation

Duckbill toes (2)

Pachypleurosaurus (meaning 'thick rib lizard') is a genus of pachypleurosaurian that lived during the Triassic Period

Megalonyx jeffersoni, ground sloth juvenile skull, Now The West Virginia State Fossil Triceratops Many fossils of this speciesPresident, 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. On March 8, 2008 Megalonyx jeffersoni became the