, the amphibians, reptiles, birds and mammals which all descended from within an identical ancestry. Because during this manner the term “fish” is described negatively as a paraphyletic group, it is not considered a formal taxonomic grouping in systematic biology, unless it is utilized in the cladistic sense, adding tetrapods. The traditional term pisces also ichthyes is considered a typological, but not a phylogenetic type. Early fish from the fossil record are represented by a collection of small, jawless, armored fish called ostracoderms. Jawless fish lineages are mostly extinct. An extant clade, the lampreys may approximate historic pre jawed fish.