"Shastasaurus" and "Shonisaurus" had previously been interpreted as suction-feeding ichthyosaurs, but a quantitative analysis of Triassic and Jurassic ichthyosaurs by Motani and colleagues in 2013 showed that none of them had sufficiently robust hyobranchial bones nor sufficiently narrow snouts to enable suction feeding.The discovery of molariform teeth in "Cartorhynchus" led Huang and colleagues to conclude in 2020 that "Cartorhynchus" was durophagous, feeding on hard-shelled prey.