 The teleosts were first recognised as a distinct group by the German ichthyologist Johannes Peter Müller in 1844 . The name is from Greek <unk> , " complete " + osteon , " bone " . Müller based this classification on certain soft tissue characteristics which would prove to be problematic as it did not take into account the distinguishing features of fossil teleosts . In 1966 , Greenwood et al. provided a more solid classification . The oldest teleost fossils date back to the late Triassic , evolving from fish related to the bowfins in the clade Holostei . During the Mesozoic and Cenozoic they diversified , and as a result , 96 percent of all known fish species are teleosts . The cladogram shows the relationship of the teleosts to other bony fish , and to the terrestrial vertebrates ( tetrapods ) that evolved from a related group of fish . Approximate dates are from Near et al . , 2012 . 
