The Karai Formation is a Mesozoic (Albian to Turonian) geologic formation in India. Fossilized ichthyosaur remains and shark teeth have been reported from this formation.[1]
| Karai Formation | |
|---|---|
| Stratigraphic range: | |
| Type | Geological formation |
| Sub-units | Odiyam & Kunnam Members |
| Underlies | Unconformity with the Kulakkalnattam formation |
| Overlies | Uttatur Group |
| Lithology | |
| Primary | Mudstone |
| Location | |
| Coordinates | 11°00′N 78°54′E / 11.0°N 78.90°E |
| Region | Tamil Nadu, Cauvery basin |
| Country |  India |
[[File:.  Karai Formation (India) | |
Paleobiota edit
Color key
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Notes Uncertain or tentative taxa are in small text; |
Ichthyosaurs edit
| Ichthyosaurs from the Karai Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Material | Notes | Images | |
| Ichthyosauria | indet.[2] | Vertebrae. | Previously known as "Platypterygius indicus".[3] | |||
| Ichthyosaurus[4] | I. indicus | A few complete and one partially complete vertebrae. | Considered a nomen dubium.[5] | |||
| Ichthyosauria | indet.[6] | Six adult teeth, one juvenile tooth and seven partial vertebrae. | Was tentatively assigned to P. indicus. It is similar to other species of Platypterygius.[1] It was later noted that only one of the teeth can be assigned to Platypterygiinae.[6] | |||
| Platypterygius | P. sp. indet. | An Anterior caudal vertebra. | A Platypterygiine ichthyosaur.[7] | |||
edit
| Chondrichthyans from the Karai Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Material | Notes | Images | |
| Protosqualus | P. sp. | One incomplete tooth. | A Squalid shark.[1] | |||
| Gladioserratus | G. magnus | One lower lateral tooth. | A Hexanchid shark.[1] | |||
| ?Notidanodon | ?N. sp. | One tooth fragment. | A Hexanchid shark.[1] | |||
| Cretalamna | C. appendiculaia | Twenty-five teeth. | An Otodontid shark.[1] | |||
| Dwardius | D. sudindicus | Over a hundred teeth. | A Lamniform shark.[1] | |||
| ?Eostriatolamia | ?E. sp. | One upper lateral tooth and a cusp of an anterior tooth. | An Odontaspidid shark.[1] | |||
| Squalicorax | S. aff. baharijensis | Five complete and two fragmentary teeth. | An Anacoracid shark.[1] | |||
| Cretodus | C. longiplicatus | Fifteen teeth. | A Lamniform shark.[1] | |||
References edit
- ^ a b c d e f g h i j https://www.researchgate.net/publication/233085546_Marine_Vertebrates_from_the_%27Middle%27_Cretaceous_Early_Cenomanian_of_South_India
- ^ Fischer, Valentin; Bardet, Nathalie; Benson, Roger B. J.; Arkhangelsky, Maxim S.; Friedman, Matt (2016-03-08). "Extinction of fish-shaped marine reptiles associated with reduced evolutionary rates and global environmental volatility". Nature Communications. 7 (1): 10825. Bibcode:2016NatCo...710825F. doi:10.1038/ncomms10825. ISSN 2041-1723. PMC 4786747. PMID 26953824.
- ^ Foote, Robert Bruce; Lydekker, Richard (1874). Indian Tertiary and post Tertiary Vertebrata. Calcutta: Geological Survey Office [etc., etc.] doi:10.5962/bhl.title.125505.
- ^ Lydekker, R. (July 1888). "VI.—Note on the Classification of the Ichthyopterygia (with a Notice of Two New Species)". Geological Magazine. 5 (7): 309–314. Bibcode:1888GeoM....5..309L. doi:10.1017/s0016756800181968. ISSN 0016-7568.
- ^ https://www.redalyc.org/pdf/505/50510405.pdf
- ^ a b Fischer, Valentin (2016-10-20). "Taxonomy ofPlatypterygius campylodonand the diversity of the last ichthyosaurs". PeerJ. 4: e2604. doi:10.7717/peerj.2604. ISSN 2167-8359. PMC 5075704. PMID 27781178.
- ^ Ayyasami, K.; Elamparuthi, S.; Gowtham, B. (2016-06-01). "An ichthyosaur vertebra from the Cretaceous (Middle Cenomanian) Karai Formation, southern India". Journal of the Geological Society of India. 87 (6): 706–708. Bibcode:2016JGSI...87..706A. doi:10.1007/s12594-016-0442-5. ISSN 0974-6889.