One specimen has been recovered from the late Paleocene-aged Tongue River Member 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.

Indeterminate remains are known from worldwide, including the Gulf Coast of the United States (Alabama, Arkansas, and Texas),[15] Australia, Belgium, Lebanon, and Russia.

[17] 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.

[19] 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.