Osteichthyes are a taxonomic superclass of fish, also called bony fish that includes the ray-finned fish (Actinopterygii) and lobe finned fish (Sarcopterygii).
The osteichthyes are paraphyletic with land vertebrates, in some classification schemes the tetrapods et al are considered to be members of the osteichthyes for this reason.
Most bony-fish belong to the Actinopterygii; there are only eight living species of lobe finned fish (Sarcopterygii) including the lungfish and coelacanths. (Some species of lobe-finned fish have jointed bones.)
They are traditionally treated as a class of vertebrates, with subclasses Actinopterygii and Sarcopterygii, but some newer schemes divide them into several separate classes.
The vast majority of fish are osteichthyes. Osteichthyes are the most various group of vertebrates, consisting of over 29,000 species, making them the largest class of vertebrates in existence today.