Crossognathiformes

Crossognathiformes is an extinct order of ray-finned fish that lived from the Late Jurassic to the Eocene. Its phylogenetic placement is disputed; some authors have recovered it as part of the teleost stem group, while others place it in a basal position within crown group Teleostei. Other placements have found it to be polyphyletic, with Varasichthyidae being stem-group teleosts whereas the other, "true" crossognathiforms are crown-group teleosts within Teleocephala.

The oldest definitive crossognathiforms are known from the Late Jurassic (Oxfordian) of Chile. They diversified afterwards and became a dominant group of marine fish throughout much of the Cretaceous. The last surviving member was the pachyrhizodontid Platinx from the Eocene.