Lytoceras

Lytoceras is an ammonite genus that was extant during most of the Jurassic and Cretaceous periods, and is the type genus for the family Lytoceratidae. These cephalopods were fast-moving nektonic carnivores.

==Description== thumb|left|The giant L. taharoaense, Auckland War Memorial Museum Shells of Lytoceras are evolute, round or quadrate in section, covered with crinkled growth lines or riblets, and may have slight constrictions on internal molds. Some have fine striations, (parallel grooves running longitudinally along the flanks).