Essexella asherae, Mazon Creek Jellyfish Replica Compsognathus Despite the name

Despite the name

All families of Carnivora are thought to be derived from the Miacids

the western United States

" an appropriate descriptor

Essexella asherae, Mazon Creek Jellyfish Replica Compsognathus Despite the nameJellyfish are extremely rare in the fossil record. This is hardly surprising, considering they completely lack hard parts, and the tissues they do possess are gelatinous. One of the most famous deposits containing fossil jellyfish is the Pennsylvanian aged Mazon Creek Lagersttte near Chicago, Illinois. In the Mazon Creek area, the Francis Creek Shale consists of concretionary gray shales. The Francis Creek concretions are sideritic, and can be