Actinopterygii

Ray-finned fish Temporal range: Late Silurian–Present, 425–0 Ma[1] PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Superclass:	Osteichthyes
Class:	Actinopterygii Klein, 1885
Subclasses
Cladistia (bichirs) Actinopteri Chondrostei (sturgeon and paddlefish) Neopterygii Holostei (bowfin and gars) Teleostei

The Actinopterygii is the class of ray-finned fishes.

The ray-finned fishes get their name from the fact their fins are webs of skin held by bony or horny spines ("rays"). This is different from the fleshy fins of the fish in the Sarcopterygii. Ray-finned fish first appeared in the Silurian period.

Actinopterygians are the largest class of vertebrates. There are nearly 25,000 species. They can be found in both fresh water and marine environments from the deep sea to the highest mountain streams.

Most of the living species are teleosts, which are late-comers to the fish domain. The first teleosts are in the Mesozoic era, yet now they make up 96% of all fish.^[2]

1. ↑ Zhao, W.; Zhang, X.; Jia, G.; Shen, Y.; Zhu, M. (2021). "The Silurian-Devonian boundary in East Yunnan (South China) and the minimum constraint for the lungfish-tetrapod split". Science China Earth Sciences. 64 (10): 1784–1797. Bibcode:2021ScChD..64.1784Z. doi:10.1007/s11430-020-9794-8. S2CID 236438229.
2. ↑ R. Froese; D. Pauly, eds. (February 2006). "FishBase".