Cladistia

Not to be confused with Cladistics.

Cladistia
Temporal range: Early Triassic–present (Possible Permian and Carboniferous records)
Polypterus senegalus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Subclass: Cladistia
Pander 1860 emend. Cope 1871 sensu Lund 2000
Orders

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 Carboniferous.[2] 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.[3]

Aside from bichirs, other extinct fish groups thought to be members of the group include the Scanilepiformes, known from Triassic (and possibly Permian[4]) of the Northern Hemisphere.[5][2][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 a stem-group to Neopterygii.[6][7]

  1. ^ Lecointre G, Le Guyader H (2007). The Tree of Life: A Phylogenetic Classification. Harvard University Press Reference Library. ISBN 978-0-674-02183-9.
  2. ^ a b 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.
  3. ^ 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.
  4. ^ 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.
  5. ^ 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.
  6. ^ 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.
  7. ^ "The new Actinopterygian order Guildayichthyiformes from the Lower Carboniferous of Montana (USA)". Geodiversitas. 22 (2): 171–206. 2000.