The extinct families Sclerorhynchidae and Ptychotrygonidae had long, serrated rostrums very similar to those of extant sawsharks and sawfishes, and their relation to them has been debated. A 2004 study found sawsharks to actually be the most basal of batoids rather than true sharks, with the order Sclerorhynchiformes containing Sclerorhynchidae and Ischyrhizidae and forming a sister group to sawfish and all other rays, with the clade containing sawsharks and rays being coined Pristiorajea. However, further studies have affirmed that sawsharks are true sharks and a member of Selachimorpha. A 2019 study instead found Sclerorhynchiformes to be a paraphyletic assemblage of rays within Rajiformes and leading up to Rajidae, and thus downgraded Sclerorhynchidae and Ptychotrygonidae to being families within the suborder Sclerorhynchoidei of the order Rajiformes, with "Ischyrhiza", "Schizorhiza", and "Onchopristis" not belonging within Sclerorhynchidae despite their similar appearance, and instead forming an unnamed sister group to Rajidae itself.