Karai Formation | |
---|---|
Stratigraphic range: Albian to Turonian ~ | |
Type | Geological formation |
Sub-units | Odiyam & Kunnam Members |
Underlies | Unconformity with the Kulakkalnattam formation |
Overlies | Uttatur Group |
Lithology | |
Primary | Mudstone |
Location | |
Coordinates | 11°00′N78°54′E / 11.0°N 78.90°E |
Region | Tamil Nadu, Cauvery basin |
Country | India |
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]
Color key
| Notes Uncertain or tentative taxa are in small text; |
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] |
| 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] |
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] | |||
Mollusks from the Karai Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Material | Notes | Images | |
Acanthoceras | A. rhotomagense | An Acanthoceratidae Ammonite. | ||||
Calycoceras |
| An Acanthoceratidae Ammonite. | ||||
Pseudocalycoceras |
| An Acanthoceratidae Ammonite. | ||||
Kunnamiceras | K. tropicum | An Acanthoceratidae Ammonite. | ||||
Eucalycoceras | E. pentagonum | An Acanthoceratidae Ammonite. | ||||
Lotzeites | L. aberrans | An Acanthoceratidae Ammonite. | ||||
Desmoceras |
| A Desmoceratidae Ammonite. | ||||
Sciponoceras | sp. | A Baculitidae Ammonite. | ||||
Phylloceras | P. seresitense | A Phylloceratidae Ammonite. | ||||
Holcodiscoides | H. elegans | A Kossmaticeratidae Ammonite. | ||||
Cymatoceras | C. huxleyanum | A Nautilidae. | ||||
Eutrephoceras | E. justum | A Nautilidae. | ||||
Pycnodonte | P. vesicularis | An Oyster. |