Chiromystus
| Chiromystus Temporal range: Early Cretaceous,
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|---|---|
| Fossil specimen of C. alagoensis | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | †Ichthyodectiformes |
| Family: | †Cladocyclidae |
| Genus: | †Chiromystus Cope, 1886 |
| Type species | |
| †Chiromystus mawsoni Cope, 1886
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| Species | |
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See text | |
| Synonyms | |
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Chiromystus is an extinct genus of freshwater ichthyodectiform ray-finned fish that inhabited large rift lakes on the supercontinent of West Gondwana during the Early Cretaceous.[1][2][3] Three to four species are known from both of West Gondwana's constituent continents (South America & Africa).[4]
The following species are known:[2]
- C. alagoensis Jordan, 1910 - Aptian of Alagoas, Brazil (Muribeca Formation)[5]
- C. guinensis (Weiler, 1922) - Aptian of Equatorial Guinea & Gabon (Cocobeach Formation) (=?Chirocentrites guinensis Weiler, 1922)[4]
- C. mawsoni Cope, 1886 (type species) - late Hauterivian/early Barremian of Bahia, Brazil (Marfim Formation of Bahia Group),[6] Aptian of Alagoas, Brazil (Muribeca Formation)[7][8]
- ?C. woodwardi Silva-Santos, 1947 - late Hauterivian/early Barremian of Bahia, Brazil (Marfim Formation)[6] (=Itaparica woodwardi (Silva-Santos, 1947))[8]
The classification of C. woodwardi remains uncertain. It was initially confused with C. mawsoni before being described as a distinct species in 1947. In 1986, it was reclassified into its own genus, Itaparica, but the basis for this reclassification is scant, and it is thus tentatively retained in Chiromystus.[8]
Chiromystus was initially classified in the family Chirocentridae (the modern wolf-herrings) before being moved into the extinct Ichthyodectiformes.[7] This genus was also initially synonymized with the related but marine genus Cladocyclus for a time.[8]
A partial ichthyodectiform skull reminiscent of either Chiromystus or Gillicus was recovered from earliest Cenomanian-aged rocks in a drill core taken from the Cape Verde Rise in the southern Atlantic Ocean, about 699.9 metres (2,296 ft) below the surface. The morphology of the specimen closely resembles that of Chiromystus, as does its occurrence in between South America and Africa, but it appears to have inhabited marine habitats, in contrast to Chiromystus which inhabited freshwater and estuarine habitats.[9]
References
- ^ "PBDB". paleobiodb.org. Archived from the original on 2021-12-09. Retrieved 2026-06-08.
- ^ a b Lindoso, Rafael Matos; Maisey, John Graham; Carvalho, Ismar de Souza (2016-04-01). "Ichthyofauna from the Codó Formation, Lower Cretaceous (Aptian, Parnaíba Basin), Northeastern Brazil and their paleobiogeographical and paleoecological significance". Palaeogeography, Palaeoclimatology, Palaeoecology. 447: 53–64. doi:10.1016/j.palaeo.2016.01.045. ISSN 0031-0182.
- ^ Maisey, John G. (2016). "Mr Mawson's fossils". Geological Society, London, Special Publications. 430 (1): 219–233. doi:10.1144/SP430.2. ISSN 0305-8719.
- ^ a b Taverne, Louis (2010). "Les Ichthyodectidae (Teleostei, Ichthyodectiformes) des schistes bitumineux de l'Aptien (Crétacé inférieur) de Guinée Équatoriale et du Gabon". Bulletin de l'Institut Royal des Sciences Naturelles de Belqique, Sciences de la Terre. 80: 115–143.
- ^ Jordan, David Starr (1898). Collected papers.
- ^ a b "PBDB". paleobiodb.org. Retrieved 2026-06-08.
- ^ a b Cope, E. D. (1886). "A Contribution to the Vertebrate Paleontology of Brazil". Proceedings of the American Philosophical Society. 23 (121): 1–21. ISSN 0003-049X.
- ^ a b c d Cavin, Lionel; Forey, Peter L.; Giersch, Samuel (2013-02-01). "Osteology of Eubiodectes libanicus (Pictet & Humbert, 1866) and some other ichthyodectiformes (Teleostei): phylogenetic implications". Journal of Systematic Palaeontology. 11 (2): 115–177. doi:10.1080/14772019.2012.691559. ISSN 1477-2019.
- ^ Casson, Max; Cavin, Lionel; Jeremiah, Jason; Bulot, Luc G.; Redfern, Jonathan (2018-09-03). "Fishing in the Central Atlantic, an earliest Cenomanian ichthyodectiform from DSDP Site 367, Cape Verde Basin". Journal of Vertebrate Paleontology. 38 (5) e1510415. doi:10.1080/02724634.2018.1510415. ISSN 0272-4634.