{{Short description|Geological formation in Southern India }} {{Infobox rockunit | name = Anaipadi formation | type = Geological formation | age = Coniacian <br />~{{fossil range|88|86}} | period = Coniacian | underlies=Ariyalur Group | country = {{flag|India}} | coordinates = | extent = }}
The '''Anapadi Formation''' is a geological formation dating back to the Late Cretaceous Period (Coniacian) of India.<ref name=":0">{{Cite journal |last=Verma |first=Omkar |date=2015 |title=Cretaceous vertebrate fauna of the Cauvery Basin, southern India: Palaeodiversity and palaeobiogeographic implications |url=https://linkinghub.elsevier.com/retrieve/pii/S0031018215002229 |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |language=en |volume=431 |pages=53–67 |doi=10.1016/j.palaeo.2015.04.021|bibcode=2015PPP...431...53V |url-access=subscription }}</ref> == Description == The Anaipadi Formation preserves fossils from a neritic environment (the relatively shallow part of the ocean above the drop-off of the continental shelf).<ref name=":0" /> The upper portion of the unit, which is marked by the presence of the ammonite Kossmaticeras theobaldianum.<ref name=:2>{{Cite journal |last1=Yadagiri |first1=P. |last2=Ayyasami |first2=K. |date=1979-11-01 |title=A New Stegosaurian Dinosaur from Upper Cretaceous Sediments of South India |url=https://doi.org/10.17491/jgsi/1979/201101 |journal=Journal of the Geological Society of India |volume=20 |issue=11 |pages=521–530 |doi=10.17491/jgsi/1979/201101 |bibcode=1979JGSI...20..521Y |issn=0974-6889|url-access=subscription }}</ref> The Anaipadi Formation preserves a rich mollusc fauna.<ref name=":0" /> including common fossils of ammonites and inoceramids, as well as brachiopods.<ref name=":1">{{Cite journal |last=Ayyasami |first=Krishnan |date=2006 |title=Role of oysters in biostratigraphy: A case study from the Cretaceous of the Ariyalur area, southern India |url=http://link.springer.com/10.1007/BF02910367 |journal=Geosciences Journal |language=en |volume=10 |issue=3 |pages=237–247 |doi=10.1007/BF02910367 |bibcode=2006GescJ..10..237A |issn=1226-4806|url-access=subscription }}</ref> Fossils of marine reptiles have also been found, although they are rare.<ref name=":0" /> It has been suggested that the abundant brachiopods and inoceramids in the upper Anaipadi Formation indicates a transgressive environment.<ref name=":1" />
In addition to the marine life found in the upper Anaipadi Formation, terrestrial matter was in the area evidently prone to being carried out to sea. Among other finds recovered in the unit are for instance a large amount of petrified wood.<ref name=":1" /> The presence of large quantities of wood indicates that land with dense vegetation was located relatively close a marine environment<ref name=":2" />
== Fossil Content == Rare fossils of Marine Reptiles are found in the Anaipadi formation as well.<ref name=":0" /> {| class="wikitable" align="center" width="75%" |- ! colspan="6" align="center" | Dinosaurs of the Anaipadi formation |- ! Genus !! Species !! Location !! Material !! Notes !! Images |- |''Dravidosaurus'' |''D. blanfordi'' |West of the village of Siranattam |GSI SR Pal 1, a partial skull, as well as fossils identified as an isolated tooth, a sacrum, an ilium, an ischium, ten armor plates, and a tail spike, designated (in order) as GSI SR Pal 2–7.[7] Yadigiri and Ayyasami identified several of the skull bones in GSI SR Pal 1, of which the most well-preserved were the parietals, frontals, supraorbitals, squamosal, and quadrate.In addition to the armor plate GSI SR Pal 6, nine other fossils identified as armor plates were found associated with the referred specimens. |A possible late surviving Stegosaur | thumb|Skull diagram of ''Dravidosaurus'' |} {| class="wikitable" align="center" width="75%" |- ! colspan="6" align="center" | Sharks of the Anaipadi formation |- ! Genus !! Species !! Location !! Notes !! Material !! Images |- |''Squalicorax'' |''S''.sp. | |A lamniform shark | | thumb|Squalicorax falcatus |- |''Dwardius'' |''D''. sp. | |A cardabiodontid lamniform shark | |thumb |- |''Cretalamna''? |''C''.? sp. | |An Otodontid lamniform shark | |thumb|''Cretalamna'' |- |''Eostritolamia'' |''E''. sp. | |An Odontaspitid lamniform shark | | |- |''Protosqualus'' |''P''. sp. | |A dogfish | |thumb |- |''Gladioserratus''? |''G''.? sp | |A cow shark | | |} {| class="wikitable" align="center" width="75%" |- ! colspan="6" align="center" | Molluscs of the Anaipadi formation |- ! Genus !! Species !! Location !! Material !! Notes !! Images |- |''Kossmaticeras'' |''K. theobaldianum'' | | |A Kosmaticeratid ammonite |} The formation also contains fossils of other ammonites, inoceramids and brachiopods.<ref name=":1" />
==References== {{reflist}}
Category:Geologic formations Category:Geology of India