Actinopteri

Actinopteri (/æktɪˈnɒptəraɪ/) is the sister group of Cladistia (bichirs) in the class Actinopterygii (ray-finned fish).

Actinopteri
Atlantic sturgeon (Chondrostei)
Atlantic salmon (Neopterygii)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
(unranked):	Actinopteri Cope, 1871
Subclasses
Chondrostei Neopterygii

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Dating back to the Permian period, the Actinopteri comprise the Chondrostei (sturgeons and paddlefish), the Holostei (bowfins and gars), and the teleosts; in other words, all extant ray-finned fish other than the bichirs.

In this clade the lungs have evolved into a swim bladder.^[1]

Characters of Actinopteri include ^[2] paired fin structure, a single dorsal fin, fulcra, a large median gular and numerous branchiostegals, ganoid scales, and a valvula cerebelli in the brain.

Classification

The following cladogram^[3][4][5][6] summarizes the evolutionary relationships of extant Actinopteri. Divergence time for each clade in mya are based on:^[7]

Actinopteri 400 mya	Chondrostei Acipenseriformes (sturgeons, paddlefish) Neopterygii 360 mya Teleostei 310 mya Holostei 275 mya Halecomorphi Amiiformes (bowfin) Ginglymodi Lepisosteiformes (gars, alligator gars)

References

1. Funk, Emily; Lencer, Ezra; McCune, Amy (September 2020). "Dorsoventral inversion of the air-filled organ (lungs, gas bladder) in vertebrates: RNA-sequencing of laser capture microdissected embryonic tissue". Journal of Experimental Zoology. Part B, Molecular and Developmental Evolution. 334 (6): 325–338. Bibcode:2020JEZB..334..325F. doi:10.1002/jez.b.22998. PMC 8094346. PMID 32864827.
2. Patterson, Colin (1982). "Morphology and Interrelationships of Primitive Actinopterygian Fishes". American Zoologist. 22 (241): 241–259. doi:10.1093/icb/22.2.241.
3. Betancur-R (2016). "Phylogenetic Classification of Bony Fishes Version 4". Archived from the original on 2017-07-11. Retrieved 2017-03-29.
4. Nelson, Joseph, S. (2016). Fishes of the World. John Wiley & Sons, Inc. ISBN 9781118342336.{{cite book}}: CS1 maint: multiple names: authors list (link)
5. "Actinopterygii". Integrated Taxonomic Information System. Retrieved 3 April 2006.
6. R. Froese and D. Pauly, ed. (February 2006). "FishBase".
7. Thomas J. Near; et al. (2012). "Resolution of ray-finned fish phylogeny and timing of diversification". PNAS. 109 (34): 13698–13703. Bibcode:2012PNAS..10913698N. doi:10.1073/pnas.1206625109. PMC 3427055. PMID 22869754.