phaeodonta

Phaeodonta is a subclass of ray-finned fish that includes the majority of living bony fish. The name "phaeodonta" comes from the Greek words "phaeos," meaning "dark," and "odontos," meaning "tooth," referring to the darkly pigmented teeth of many species. This subclass is characterized by the presence of a single, unpaired median fin, which is typically located on the dorsal surface of the body. The median fin is used for balance and stability during swimming. Phaeodonta is further divided into two infraclasses: Holostei, which includes the lungfish and coelacanths, and Neopterygii, which includes all other ray-finned fish. The subclass Phaeodonta is one of the most diverse and successful groups of vertebrates, with over 28,000 known species.