Tullimonstrum gregarium, Tully Monster (Pit 11) 964c4db65f9489e6f6012b3ec2a0cea1 Nantan County

Nantan County

Scientists believe they were fast runners

This comes from small amounts of chromium replacing some of the aluminum

pearls from freshwater mollusks

The animals survived until the Permian Period

Tullimonstrum gregarium, Tully Monster (Pit 11) 964c4db65f9489e6f6012b3ec2a0cea1 Nantan CountyTullimonstrum gregarium, popularly known as The Tully Monster, is the Illinois State Fossil & is perhaps one of the most mysterious fossils ever unearthed Age of the Tully Monster During the Pennsylvanian Period (roughly 307 million years ago), the land that is now Illinois lay near Earth's equator. Dense swamps, forested with primitive plants, covered much of western and central Illinois. In shallow seas nearby, the Tully monster swam along with