| Caseodontidae Temporal range: Early Carboniferous to Early Triassic
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|---|---|
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| Life restoration of Caseodus, the type genus | |
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| The skull of Ornithoprion, an aberrant caseodont | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Subclass: | Holocephali |
| Order: | †Eugeneodontida |
| Clade: | †Caseodontoidea |
| Family: | †Caseodontidae Zangerl, 1981 |
| Type genus | |
| Caseodus Zangerl, 1981
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| Type species | |
| Orodus basalis (=Caseodus basalis) Cope, 1894
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| Genera | |
The Caseodontidae is an extinct family of eugeneodont holocephalans known from the late Paleozoic to earliest Mesozoic of Greenland, Canada and the United States.[1][2] Members of the group are characterized by a reduced or absent palatoquadrate, elongate upper and mandibular rostra, and bulbous, crushing dentition, including a small symphyseal whorl of teeth on the lower jaw and batteries of teeth fused directly to the neurocranium.[3][4] Several genera are known from partial or complete body fossils.[3][5]
Unlike the distantly related helicoprionids, members of this family crossed the Permian-Triassic boundary and persisted into the Olenekian stage of the Early Triassic,[5] after which they became extinct. It is hypothesized that in life caseodonts fed on hard-shelled prey such as brachiopods due to their crushing tooth batteries,[4] and it has been proposed that the elongated rostra on the upper and lower jaws of some genera was an adaptation for prying prey off of the seabed.[6] Well preserved specimens are known from the Carboniferous of Nebraska and Indiana,[3] deposits in East Greenland,[2] and from the Sulphur Mountain Formation of British Columbia, which is the last known appearance of the group.[5]
References
[edit]- ^ "Caseodontidae". Mindat.org. Retrieved 21 August 2024.
- ^ a b "Caseodontidae". Global Biodiversity Information Facility (GBIF). Retrieved 21 August 2024.
- ^ a b c Zangerl, Rainer (1 January 1981). Chondrichthyes 1: Paleozoic Elasmobranchii (Handbook of Paleoichthyology). Friedrich Pfell. ISBN 978-3899370454.
{{cite book}}: CS1 maint: date and year (link) - ^ a b Mutter, Raoul; Neuman, Andrew (10 June 2008). "Jaws and dentition in an Early Triassic, 3-dimensionally preserved eugeneodontid skull (Chondrichthyes)". Acta Geologica Polonica. 58: 223–227.
- ^ a b c Mutter, Raoul J.; Neuman, Andrew G. (2008). "New eugeneodontid sharks from the Lower Triassic Sulphur Mountain Formation of Western Canada". Geological Society, London, Special Publications. 295 (1): 9–41. Bibcode:2008GSLSP.295....9M. doi:10.1144/sp295.3. ISSN 0305-8719.
- ^ Alexander, Richard R. (1981). "Predation Scars Preserved in Chesterian Brachiopods: Probable Culprits and Evolutionary Consequences for the Articulates". Journal of Paleontology. 55 (1): 192–203. ISSN 0022-3360. JSTOR 1304340.