Cladistia is a clade of bony fishes whose only living memebrs are the bichirs.[1] 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.