Deformities in the Late Callovian (Late Middle Jurassic) Ammonite Fauna from Saratov, Russia

Like other molluscs, every ammonite carries a record of its ontogeny and, commonly, its death, in its shell. Traumatic life events such as bites, diseases, epizoa, and diet all left evidence in the shell as scars, blisters, disfigurations, holes, nicks, crushing, attachments, and abnormalities, along with slow, rapid, stunted, or enlarged growth. If an ammonite survived bites due to predation, its shell documented the damage. Often, the cause and stage of life when that injury happened can, at times, be interpreted and diagnosed. If an ammonite did not survive the attack, its shell commonly exhibits holes or missing portions. If most of the ammonite was consumed, only parts, pieces, or fragments of the shell will be found.