Belonostomus (from , 'dart' and 'mouth') is a genus of prehistoric ray-finned fish that was described by Louis Agassiz in 1844. It is a member of the order Aspidorhynchiformes, a group of fish known for their distinctive elongated rostrums. The oldest known species are from the Upper Jurassic of Germany, with the youngest known species from the late Paleocene. Fossils of Belonostmus have been found worldwide in marine deposits. It likely consumed plankton or other small fish.
Belonostomus species include: Belonostomus kochii Belonostomus acutus Belonostomus carinatus Belonostomus crassirostris Belonostomus indicus Belonostomus longirostris Belonostomus münsteri Belonostomus tenuirostris