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Helicoprionidae
Family of fossil fish / From Wikipedia, the free encyclopedia
Helicoprionidae (synonym Agassizodontidae) is an extinct, poorly known family of bizarre holocephalids within the poorly understood order Eugeneodontida. Members of the Helicoprionidae possessed a unique "tooth-whorl" on the symphysis of the lower jaw and pectoral fins supported by long radials.[2] The closest living relatives of the Helicoprionidae and all other eugeneodontids are the ratfishes. The anatomy of the tooth-whorl differed amongst genus and species, some possessing complete spirals (such as those of Helicoprion), others possessing halved spirals (seen in Parahelicoprion), and some with wedged half-spirals (seen in Sarcoprion). Each tooth-whorl is thought to be adapted to a different type of prey, and a different predation strategy.[3]
Helicoprionidae | |
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Helicoprion | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Chondrichthyes |
Subclass: | Holocephali |
Order: | †Eugeneodontida |
Clade: | †Edestoidea |
Family: | †Helicoprionidae Karpinsky, 1911 |
Type genus | |
Helicoprion Karpinsky, 1899[1] | |
Type species | |
Helicoprion bessonowi Karpinsky, 1899 | |
Genera | |
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Synonyms | |
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