It contains two valid species, O. numida and O. dunklei, though some researchers argue that both may be considered a single taxon with variation in morphology caused by a wide geographical range.

[12] Specimens of Onchopristis have been discovered in coastal and fluvial deposits dated from the Barremian to the Cenomanian ages (~125-94 mya),[1] making this genus one of the oldest known sclerorhynchoid.

[14] Oral teeth from the Bahariya Formation of Egypt were named Squatina aegyptiaca by Stromer in 1927, and were later renamed as the separate genus Sechmetia by Christa Werner in 1989.

[19][12] An uncritical summary of 70 vertebrate taxa found in the Aguja Formation reports the presence of O. dunklei based on two fragmentary specimens, though the authors acknowledge the skepticism regarding the Campanian-Maastrichtian occurrence of this genus.

[21][22] In 2019, the isolated rostral denticles found in the possible late Maastrichtian-Paleocene strata from Mali were attributed to O. numida,[23] but these specimens more likely represent cutlassfish fangs.

[24] In 2024, four fragmentary rostral denticles and an exceptionally large, 1.46 metres (4.8 ft) long rostrum of sclerorhynchoids from the Maastrichtian-aged Dakhla Formation of Egypt were referred to as Onchopristis sp.

[25] However, Greenfield (2025) argued that neither of the referred material from the Dakhla Formation can be assigned to Onchopristis, and he reidentified the rostrum as an indeterminate sclerorhynchoid and the unassociated rostral denticles as Sclerorhynchus cf.