Apateon

• †Apateon caducus
• †Apateon dracyi
• †Apateon flagrifer
• †Apateon kontheri
• †Apateon pedestris von Meyer 1840
• †Apateon umbrosus

Fossils of Apateon are found in freshwaters strata of Latest Carboniferous (Gzhelian) to Early Permian (Asselian) of Germany.

These amphibians could reach a length of about 5-12 centimetres (2.0-4.7 in), while the length of the skull could reach 8-24 millimetres (0.31-0.94 in). They resembled a salamander and had a laterally flattened tail with a long fin. The body was completely covered with rounded scales. The portion of the skull behind the eyes was quite short. On opposite sides of the head there are three pairs of long, spiral-shaped external gills. They had a weakly ossified skeleton and a wide, short skull, with huge eye holes. The teeth were small and peaked. On the hands are present four fingers.

Life history

Like some modern salamanders, Apateon caducus had two different trajectories of life history. One was metamorphosis, which involved ossification of the braincase, palatoquadrate, and intercentra, and the other being neoteny. Apateon were sexually mature in the neotenous state in which adults retained traits seen in the young, such as larval-type sculpting of the dermal portion of the skull roof and ossified branchial denticles. Neotenous Apateon were fully aquatic animals that lived in semi-permanent lakes and ponds, while metamorphosed individuals had the ability to engage in terrestrial locomotion.

Diet

Apateon fed on microorganisms. However, in exceptionally harsh environmental conditions, the species Apateon gracilis engaged in cannibalism.