†suborder Hexanchoidei Hay 1902 (elasmobranch)
Chondrichthyes - Hexanchiformes
Alternative spelling: Hexanchoidea
Full reference: O. P. Hay. 1902. Bibliography and Catalogue of the Fossil Vertebrata of North America. Bulletin of the United States Geological Survey 179:1-868
Parent taxon: Hexanchiformes according to S. Stumpf and J. Kriwet 2019
See also Cahuzac et al. 2007, Hay 1902, Kumar and Loyal 1987, Landau et al. 2025, Maisey 1986 and Popov et al. 2025
Sister taxa: Chlamydoselachidae, Crassonotidae, Heptranchidae, Hexanchidae, Komoksodontidae, Orthacodidae, Paraheptranchias, Paranotidanus
Subtaxa: Crassodontidanidae
Ecology: nektonic carnivore
Distribution: