Description

Macrocephalites is a genus of the stephanoceratoid ammonite family Macrocephalitidae, diagnostic of the Callovian stage of the Middle Jurassic. 

Ammonites are extinct members of the cephalopod group of mollusks. Only a limited number of species have survived to the present day which includes the squid and the chambered nautilus. Ammonites had a multi-chambered shell, and added more chambers as it grew, always living in the outer chamber. They lived in the Cretaceous period some 63 to 130 million years ago.

Trigonia is an extinct genus of saltwater clams, fossil marine bivalve mollusk in the family Trigoniidae. The fossil range of the genus spans the Paleozoic, Mesozoic and Paleocene of the Cenozoic, from 298 to 56 Ma.