FISH
Rhinocephalus planiceps

Fish are generally covered in scales and have fins and a propulsive tail. There are several classes, Agnatha without jaws, the extinct Placodermi, modern Osteichthyes with a bone skeleton and Chondrichthyes with a cartilage skeleton.

The Eocene of Sheppey is famous for its fossil fish preserved in three dimensions like the skull of Rhinocephalus planiceps shown in the picture.

Skull of Eocene fish, Rhinocephalus planiceps, from Sheppey, Kent