Fossils of Belonostomus have been found worldwide in marine deposits, although some species are known from freshwater habitats.[3] The oldest known species are from the Upper Jurassic of Germany and England, with the youngest known species from the late Maastrichtian. One specimen has been recovered from the late Paleocene of North Dakota, which would suggest that this genus was the only aspidorhynchean to survive into the Cenozoic, although it is possible this fossil may have been reworked from earlier formations.[3][4]
It likely consumed plankton or other small fish,[5] though one specimen from the Late Jurassic of Germany was found with the rhynchocephalian Homoeosaurus as stomach contents.[6]
B. leptosteus Agassiz ex Egerton, 1836 - Bathonian of England (nomen dubium)[8]
B. lesinaensis Bassani, 1882 - Cenomanian of Croatia and Slovenia (possibly synonymous with B. crassirostris)[10] (syn: Hemirhynchus heckelii Kner, 1867)[8]
B. longirostris Lambe, 1902 - Santonian to late Maastrichtian of the Americas, including Canada (Alberta & Saskatchewan), the United States (Montana, North Dakota & Wyoming), Argentina, and Chile[14]
B. marquesbritoi Taverne & Capasso, 2012 - Campanian/Maastrichtian of Italy
B. matteuzi Gorjanović-Kramberger, 1895 - Cenomanian of Slovenia
B. muensteri Agassiz, 1844 - Tithonian of Germany[13] (syn: B. speciosus Wagner, 1863)[8]
B. novaki Gorjanović-Kramberger, 1895 - Cenomanian of Croatia
B. sphyraenoides Agassiz, 1844 - Tithonian of Germany (syn: B. brachysomus Agassiz, 1837, B. angustus zu Münster ex von Leonhard & Bronn, 1842)[8][13]
B. tenuirostris (Agassiz, 1833) - Tithonian of Germany[13] and France (type species) (syn: Aspidorhynchus tenuirostris Agassiz, 1833, B. subulatus Agassiz, 1834, B. ventralis Agassiz, 1834)[8]
Indeterminate remains are known from worldwide, including the Gulf Coast of the United States (Alabama, Arkansas, and Texas),[15] Australia, Belgium, Lebanon, and Russia.[2]
The former species B. acutus Agassiz, 1844 (syn: B. tenellus Agassiz ex Egerton 1841) and B. anningiae Agassiz, 1843 from the early-mid Jurassic of England are now thought to be species of the unrelated saurichthyiformSaurorhynchus.[16] The former species B. carinatus Mawson and Woodward, 1907 from the Hauterivian of Brazil is now thought to be a stem-gar in the family Obaichthyidae.[17] The former species B. microcephalus Winkler, 1862 from the Tithonian of Germany is now thought to be a junior synonym of Aspidorhynchus acustirostris, while B. flexuosus Philips, 1871 is one of A. crassus.[18] The former species B. sweeti Etheridge & Woodward, 1892 is now placed in Richmondichthys. The former species B. pygmaeus Winkler, 1874 from the Tithonian of Germany is thought to be an immature specimen of one of the other SolnhofenBelonostomus species.[7]
^ abcBrito, P. M. (1997). "Révision des Aspidorhynchidae (Pisces, Actinopterygii) du Mésozoïque : ostéologie, relations phylogénétiques, données environnementales et biogéographiques". Geodiversitas. S2CID88964324.