Clade of ray-finned fishes
Cladistia is a clade of bony fishes whose only living members are the bichirs of tropical Africa.[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 , and are thought to have diverged from the Actinopteri , the group which includes all other living ray finned fish, by the Devonian . However, the fossil range for the only extant order (Polypteriformes ) is comparatively young, only reaching as far back as the mid-Cretaceous of South America and Africa, and the two extant genera of bichir only diverged around the Miocene .[2]
Aside from bichirs, other extinct fish groups thought to be members of the group include the Scanilepiformes , known from the Middle Permian to the Late Triassic of the Northern Hemisphere.[3] [4] [5] [6] The Guildayichthyiformes of Carboniferous North America are also sometimes considered cladistians, but this is thought to be dubious, with other authorities placing them as neopterygians .[6] [7]
^ Lecointre G, Le Guyader H (2007). The Tree of Life: A Phylogenetic Classification . Harvard University Press Reference Library. ISBN 978-0-674-02183-9 .
^ Near, Thomas J.; Dornburg, Alex; Tokita, Masayoshi; Suzuki, Dai; Brandley, Matthew C.; Friedman, Matt (2014-01-02). "BOOM AND BUST: ANCIENT AND RECENT DIVERSIFICATION IN BICHIRS (POLYPTERIDAE: ACTINOPTERYGII), A RELICTUAL LINEAGE OF RAY-FINNED FISHES" . Evolution . 68 (4): 1014–1026. doi :10.1111/evo.12323 . ISSN 0014-3820 .
^ Argyriou T, Giles S, Friedman M, Romano C, Kogan I, Sánchez-Villagra MR (November 2018). "Internal cranial anatomy of Early Triassic species of †Saurichthys (Actinopterygii: †Saurichthyiformes): implications for the phylogenetic placement of †saurichthyiforms" . BMC Evolutionary Biology . 18 (1): 161. doi :10.1186/s12862-018-1264-4 . PMC 6211452 . PMID 30382811 .
^ Giles, Sam; Xu, Guang-Hui; Near, Thomas J.; Friedman, Matt (2017). "Early members of 'living fossil' lineage imply later origin of modern ray-finned fishes" . Nature . 549 (7671): 265–268. doi :10.1038/nature23654 . ISSN 1476-4687 .
^ Bakaev, A. S.; Kogan, I. (2022). "Squamation of the Permian actinopterygian Toyemia Minich, 1990: evenkiid (Scanilepiformes) affinities and implications for the origin of polypteroid scales" . www.geology.cz . Retrieved 2024-02-28 .
^ a b Near, Thomas J; Thacker, Christine E (18 April 2024). "Phylogenetic classification of living and fossil ray-finned fishes (Actinopterygii)" . Bulletin of the Peabody Museum of Natural History . 65 . doi :10.3374/014.065.0101 .
^ "The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA)" . Geodiversitas . 22 (2): 171–206. 2000.