Cladistia is a clade of bony fishes whose only living members are the bichirs. Their major synapomorphies are a heterocercal tail in which the dorsal fin has independent rays, and a posteriorly elongated parasphenoid. Cladistia are the earliest diverging branch of living Actinopterygii, sister group of Actinopteri, the group which includes all other living ray finned fish. Aside from bichirs, other extinct fish groups thought to be members of the group include the , known from the Triassic period.