Prehistoric teleostei

Ichthyodectiformes is an extinct order of marine stem-teleost ray-finned fish. The order is named after the genus Ichthyodectes, established by Edward Drinker Cope in 1870. Ichthyodectiforms are usually considered to be some of the closest relatives of the teleost crown group.

Leptolepis (from , 'slight' and 'scale') is an extinct genus of stem-teleost fish that lived in what is now Europe (Germany, Luxembourg, France, England, Italy and maybe Greece) and North of Africa (Algeria, Tunisia and Morocco) during the Jurassic period (Pliensbachian–Callovian ages).

Eurycormus is an extinct genus of prehistoric marine ray-finned fish known from the Late Jurassic. It contains a single species, E. speciosus, known from the early Tithonian-aged Eichstätt Formation of Germany.

Araripichthys is an extinct genus of marine ray-finned fish that lived from the Aptian to Coniacian stages of the Cretaceous period. The genus is named after the Araripe Basin, where it was found in the Crato and Santana Formations. Other fossils of the genus have been found at Goulmima in Morocco, the Tlayua Formation of Mexico and the Apón Formation of Venezuela.

Ascalabos is an extinct genus of marine ray-finned fish known from the Late Jurassic Solnhofen Limestone of Germany. It contains one species, A. voithii. Some authorities synonymize it with Leptolepis.

Cavenderichthys is an extinct genus of prehistoric freshwater ray-finned fish from the Late Jurassic. It contains a single species, C. talbragarensis from the Talbragar Fish beds of New South Wales, Australia.