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 paraphyletic, with the Varasichthyidae being stem-group teleosts whereas the other, "true" crossognathiforms are crown-group teleosts within the 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 Early Eocene of Monte Bolca, Italy.

Classification
Order Crossognathiformes Taverne, 1989
 * Bavarichthys Arratia & Tischlinger, 2010
 * Kradimus Veysey et al., 2020
 * Family Varasichthyidae Arratia, 1981
 * Bobbichthys Arratia, 1986
 * Domeykos Arratia & Schultze, 1985
 * Luisichthys White, 1942
 * Protoclupea Arratia et al., 1975
 * Varasichthys Arratia, 1981
 * Family Chongichthyidae Arratia, 1982
 * Chongichthys Arratia, 1982
 * Suborder Crossognathoidei Taverne, 1989
 * Family Crossognathidae Woodward, 1901 [Apsopelicidae Romer, 1966 ; Syllaemidae Cragin, 1901 ; Pelecorapidae Cragin, 1901 ]
 * Apsopelix Cope, 1871 [Helmintholepis Cockerell, 1919 ; Leptichthys Stewart, 1899 ; Palaeoclupea Dante, 1942 ; Pelecorapis Cope, 1874 ; Syllaemus Cope, 1875 ]
 * Crossognathus Pictet, 1858
 * Suborder Pachyrhizodontoidei Forey, 1977
 * Family Notelopidae Forey, 1977
 * Notelops Woodward, 1901
 * Family Pachyrhizodontidae Cope, 1872 [Greenwoodellidae Taverne, 1973 ; Thrissopatrinae Boulenger, 1904b ]
 * Apricenapiscis Taverne, 2013
 * Aquilopiscis Cumbaa & Murray, 2008
 * Cavinichthys Taverne & Capasso, 2019
 * Elopopsis Heckel, 1856
 * Goulmimichthys Cavin, 1995
 * Greenwoodella Taverne & Ross, 1973
 * Hemielopopsis Bassani, 1879
 * Lebrunichthys Taverne & Capasso, 2020
 * Michin Alvarado-Ortega et al., 2008
 * Motlayoichthys Arratia et al., 2018
 * Nardopiscis Taverne, 2008
 * Pachyrhizodus Dixon, 1850 [Acrodontosaurus Mason, 1869 ; Eurychir Jordan, 1924 ; Oricardinus Cope, 1872 ; Thrissopater Günther, 1872 sensu Forey, 1977 ]
 * Phacolepis Agassiz, 1841 [Rhacolepis Agassiz, 1841 non Frenguelli, 1942 ]
 * Platinx Agassiz, 1835
 * Polcynichthys London & Shimada, 2020
 * Rhacolepis Agassiz, 1843
 * Stanhopeichthys Taverne & Capasso, 2020
 * Tingitanichthys Taverne, 1996