Helodus
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 long.[2]
| Helodus Temporal range: | |
|---|---|
 | |
| Life reconstruction of Helodus simplex | |
Scientific 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
- 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.
- Arno Hermann Müller: Textbook of paleozoology. Volume III, Vertebrates, Part 1. Gustav Fischer Verlag, 1985.
- 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
- "Extinct - complete list | Species | Shark-References". shark-references.com. Retrieved 2020-11-29.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.