What is "teleostomi"

Teleostomi \Te"le*os`to*mi\, n. pl. [NL., fr. Gr. ? complete + ? mouth.] (Zo["o]l.) An extensive division of fishes including the ordinary fishes (Teleostei) and the ganoids.

Teleostomi is an obsolete clade of jawed vertebrates that supposedly includes the tetrapods, bony fish, and the wholly extinct acanthodian fish. Key characters of this group include an operculum and a single pair of respiratory openings, features which were lost or modified in some later representatives. The teleostomes include all jawed vertebrates except the chondrichthyans and the extinct class Placodermi.

Recent studies indicate that Osteichthyes evolved from placoderms like Entelognathus, while acanthodians are more closely related to modern chondrichthyes. Teleostoi, therefore, is not a valid, natural clade, but a polyphyletic group of unrelated species.

The clade Teleostomi should not be confused with the similar-sounding fish clade Teleostei.