Lamellaptychus cf. angulocostatus

Lamellaptychus cf. angulocostatus It is a fossil that corresponds to a aptychus, the structure that presented several functions:

• chewing apparatus.
• cover the opening (operculum) of the ammonite chamber, to protect him when he was attacked by a predator.

Aptychus are pieces that are isolated or in pairs, of chitinous or calcareous composition and are part of the chewing apparatus, contributing to the grinding of food. Most pre-Jurassic ammonites had beak-shaped jaws, similar to those of modern cephalopods. The beak can bite and tear large pieces of tissue, which are then carried to the oral cavity, to later be ingested.