Pharyngolepis oblongus, primitive jawless fish Spinosaurus a Messel frog

a Messel frog

these are thought to indicate a filter feeding lifestyle

Class: Echinoidea

Specimens are known to have been made of flint

near Frankfurt

Pharyngolepis oblongus, primitive jawless fish Spinosaurus a Messel frogPharyngolepis is an extinct genus of primitive jawless fish that lived in the Silurian period of what is now Norway. Pharyngolepis had well developed anal and caudal fins, but no paired or dorsal fins that would have helped stabilise it in the water, and so was probably a poor swimmer, remaining close to the sea bottom. The pectoral fins were instead replaced by bony spines, possibly for protection against predators, and there was a row of spines