Pterosaurs lived around the globe, researchers said, but finding skeletons is incredibly rare ... which helped during feeding ...

Placoderms are a class of prehistoric armoured fish that first appeared during ... They had internal cartilaginous skeletons like sharks and rays but with an armour-like external skeleton made ...

Previous reef-builders such as bryozoans were joined by corals and prehistoric sponges known as stromatoporoids, which formed a hard outer skeleton ... out primitive fish, which they grabbed ...