Helodus (from Greek: ἧλος helos, 'stud' and Greek: ὀδούς odoús 'tooth')[1] is an extinct genus of cartilaginous fish from the Upper Devonian through Lower Permian.[2] While the type species, H. simplex is known from an articulated specimen, the rest of the species in this genus are known entirely from isolated teeth.[3] Over twenty species have been attributed to this genus, many of which may be anterior teeth of other cartilaginous fish. This makes Helodus a wastebasket taxon.[4] For this reason, only the type species can be confidently attributed to this genus until articulated remains of other species are found.[3] H. simplex was around 30 centimeters (1 foot) long.[2]

Helodus
Life reconstruction of Helodus simplex
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Order: Helodontiformes
Family: Helodontidae
Genus: Helodus
Agassiz, 1838
Type species
Helodus simplex
Agassiz, 1838
Helodus sp. tooth from the Permian of Oklahoma, USA

References

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  1. ^ Roberts, George (1839). An etymological and explanatory dictionary of the terms and language of geology. London: Longman, Orme, Brown, Green, & Longmans. p. 76. Retrieved 30 December 2021.
  2. ^ a b Arno Hermann Müller: Textbook of paleozoology. Volume III, Vertebrates, Part 1. Gustav Fischer Verlag, 1985.
  3. ^ a b Itano, W.M., Lambert, L.L. A new cochliodont anterior tooth plate from the Mississippian of Alabama (USA) having implications for the origin of tooth plates from tooth files. Zoological Lett 4, 12 (2018). doi:10.1186/s40851-018-0097-8
  4. ^ "Extinct - complete list | Species | Shark-References". shark-references.com. Retrieved 2020-11-29.