Titanites

Titanites is an extinct ammonite cephalopod genus within the family Dorsoplanitidae, that lived during the late Tithonian of the Late Jurassic. Its fossils have been found in Canada and the United Kingdom.

Description
Species of the genus Titanites can reach large sizes, with a diameter of about 1.37 m for Titanites occidentalis. They were fast-moving nektonic carnivores.