| Named By: | Alexander Petrovich Karpinsky in 1899 |
| Time Period: | Cisuralian-Guadalupian |
| Location: | Australia - Wandagee Formation, Canada, Alberta - Ranger Canyon Formation, British Columbia - Fantasque Formation, Nunavut - Assistance Formation, China - Qixia Formation, Japan - Ochiai Formation andYagihawa limestone Formation, Kazakstan, Mexico - Patlanoaya Formation, Russia, USA, California - Goodhue Formation, Idaho - Phosphoria Formation, Montana - Phosphoria Formation, Nevada - Antler Peak Formation, Texas - Bone Spring Formation, Skinner Ranch Formation, Utah - Phosphoria Formation, Wyoming - Phosphoria Formation. The broad distribution of fossil locations suggests a global distribution |
| Size: | Uncertain but more recent estimates place larger Helicoprion at up to about 7.5 meters long. Many specimens are from smaller indviduals of about 3-4 meters long, suggesting a size variation between species |
| Diet: | Carnivore/Picivore |
| Fossil(s): | Mostly only known from the 'tooth-whorls', at least one specimen has been preserved with crushed cartilage from the skull and jaw |
| Classification: | | Chordata | Chondrichthyes | Eugeneodontida | Agassizodontidae | |
| Also known as: | | Lissoprion | |
Helicoprion is a long-lived genus of extinct, shark-like eugeneodontid holocephalid fish. Almost all fossil specimens are of spirally arranged clusters of the individuals' teeth, called "tooth whorls"-- the cartilaginous skull, spine, and other structural elements have not been preserved in the fossil record, leaving scientists to make educated guesses as to its anatomy and behavior. Helicoprion lived in the oceans of the early Permian 290 million years ago, with species known from North America, Eastern Europe, Asia, and Australia. The closest living relatives of Helicoprion (and other eugeneodontids) are the chimaeras.