Microconchs is a paleobiological term introduced by J.Callomon. This term denotes ammonites which reached maturity at a relatively small size. Microconchs also have other distinctive features: adult aperture modifications on the final apertural edge, such as lappets or long ventral rostra and a rough sculpture on the terminal body chamber. Most paleontologists believe that microconchs are shells of male ammonites, whereas macroconchs are female shells. The same type of sexual dimorphism with small-sized males and large-sized females is present in modern octopods which belong to Argonautidae family. At the same time the smallest macroconchs are often smaller than the largest microconchs (probably due to the fact that the fast-growing cephalopods reach maturity at different sizes, depending on the ambient temperature).

The text was added and/or edited by: Alex