The Amiiformes order of fish has only two extant species, the bowfins: Amia calva and Amia ocellicauda, the latter recognized as a separate species in 2022. These Amiiformes are found in the freshwater systems of North America, in the United States and parts of southern Canada. They live in freshwater streams, rivers, and swamps. The order first appeared in the Triassic, and the extinct members include both marine and freshwater species, many of which are morphologically disparate from bowfins, such as the caturids.
Evolution and diversity The extinct species of the Amiiformes can be found as fossils in Asia and Europe, but the bowfin is the last living species in the order. Amiiformes is therefore the last surviving order of Halecomorphi, the clade to which the bowfin and its fossil relatives belong. Other orders, such as the Parasemionotiformes, are all extinct.
Halecomorphs, and its sister group Ginglymodi, belong to Holostei. Holosteans are the sister group of teleosteans, the group to which nearly all (i.e., 96%) living fishes belong to. Holosteans and Teleosts form a clade called Neopterygii. The following cladogram summarizes the evolutionary relationships of living and fossil Halecomorphs, and other neopterygians.
Possible specimens of caturoids are known from the Late Triassic, with the earliest unambiguous members being known from the Early Jurassic. Amiiformes had spread to North America and Africa by the end of the Middle Jurassic, reaching an apex of diversity during the Early Cretaceous, during the Late Cretaceous and Cenozoic, the group declined until only a single genus, Amia, containing the bowfin remained.
Taxonomy Order Amiiformes Hay, 1929 Genus †Guizhouamia Liu, Yin & Wang, 2002 Genus †Otomitla Felix, 1891 Genus †Paraliodesmus Dunkle, 1969 Superfamily †Caturoidea Genus †Eurypoma Huxley, 1866 Genus †Gymnoichthys? Tintori et al., 2010 Genus †Liodesmus Wagner, 1859 Genus †Strobilodus Wagner, 1851 Family †Caturidae Owen, 1860 Genus †Catutoichthys Gouiric-Cavalli, 2016 Genus †Amblysemius Agassiz, 1844 Genus †Caturus Agassiz, 1834 Superfamily Amioidea Bonaparte, 1838 Genus †Amiidarum? Lange, 1968 [Otolith] Genus †Ferganamia? Kaznyshkin, 1990 Genus †Lehmanamia? Casier, 1966 Genus †Tomognathus Dixon, 1850 Family †Sinamiidae Berg, 1940 Genus †Ikechaoamia Liu, 1961 Genus †Siamamia Cavin et al., 2007 Genus †Sinamia Stensiö, 1935 Family Amiidae Bonaparte, 1837 Subfamily Amiinae Bonaparte, 1837 (sensu Grande & Bemis, 1998) Genus Amia Linnaeus, 1766 Genus †Cyclurus Agassiz, 1839 Genus †Pseudamiatus Whitley, 1954 Subfamily †Amiopsinae Grande & Bemis, 1998 Genus †Amiopsis Kner, 1863 Subfamily †Solnhofenamiinae Grande & Bemis, 1998 Genus †Solnhofenamia Grande & Bemis, 1998 Subfamily †Vidalamiinae Grande & Bemis, 1998 Tribe †Calamopleurini Grande & Bemis, 1998 Genus †Calamopleurus Agassiz, 1841 Genus †Maliamia Patterson & Longbottom, 1989 Tribe †Vidalamiini Grande & Bemis, 1998 Genus †Melvius Bryant, 1987 Genus †Pachyamia Chalifa & Tchernov 1982 Genus †Vidalamia White & Moy-Thomas, 1941 Genus †Nipponamia Yabumoto, 1994
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