Chondrichthyes - Eugeneodontiformes - Helicoprionidae
Synonym: Agassizodontidae Zangerl 1981
Parent taxon: Eugeneodontiformes according to W. M. Itano and S. G. Lucas 2018
See also Ginter et al. 2010, Goto and Okura 2004, Nelson 2006 and Obruchev 1964
Sister taxa: Campyloprion, Campyloprion annectans, Caseodontoidea, Edestoidea, Edistidae, Helicampodontidae, Pseudodontichthys
Subtaxa: Agassizodus Arpagodus Helicoprion Karpinskiprion Parahelicoprion Sarcoprion Toxoprion
Type: Helicoprion
Ecology: nektonic carnivore
Distribution:
• Permian of Australia (1 collection), Bolivia (1), Canada (4: Alberta, British Columbia, Nunavut), China (1), Greenland (2), Japan (2), Kazakhstan (1), Mexico (1), the Russian Federation (1), United States (24: California, Idaho, Kansas, Montana, Nevada, New Mexico, Texas, Utah, Wyoming)
• Carboniferous of Japan (1), the Russian Federation (2), United States (5: Iowa, Nebraska, New Mexico)
Total: 46 collections including 50 occurrences