Ariyalur Group

Ariyalaur Group
Stratigraphic range: Late Cretaceous to Palaeogene (Paleocene) (Campanian to Danian) ~82–65.5  Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological group
Sub-units	Sillakkudi formation, Kallakurichi Formation, Ottakovil formation, Kallamedu Formation
Underlies	Niniyur Formation
Overlies	Anaipadi Formation, Trichinopoly Group
Location
Country	India
Ariyalur Group (India) Show map of India Ariyalur Group (Tamil Nadu) Show map of Tamil Nadu

The Ariyalaur Group is a geological group in Tamil Nadu in Southern India. ^{[1] [2]}

Fossil content

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Dinosaurs from the Ariyalaur group
Genus	Species	Material	Notes	Member	Images
Abelisauridae indet. [3]		"Disassociated remains" and teeth.		Kallamedu formation
Carnosauria indet.? [4]		"Fragmentary remains".	Carnosauria was often used as a wastebasket taxon.	Kallamedu formation
Troodontidae indet. [3]		One isolated tooth (DUGF/52).		Kallamedu formation
Bruhathkayosaurus [4] [5]	B. matleyi	ilium and ischium, femur, tibia, radius and part of a vertebra (specifically a platycoelous caudal centrum). Remains no longer exist.	Initially described as a Theropod, it was reclassified as a Titanosaur.	Kallamedu formation
Sauropoda	Indeterminate. [6] [7]	"Fragmentary remains".		Kallamedu formation
Titanosauria	Indeterminate. [8]	Solitary egg.		Kallamedu formation
Titanosauria	Indeterminate. [9]	Ten large sauropod bones, some of which could be identified as a humerus or femur, proximal end of a femur and scapula. All the bones pertain to the limbs.	Similar in size to Bruhathkayosaurus. [5]	Kallamedu formation
Fusioolithus [8]	F. baghensis	Dinosaur eggs.		Kallamedu formation
?Camarasauridae [10]	Indeterminate.	Vertebrae.	Camarasaurids are not known from the cretaceous.	Kallamedu formation
?Stegosauria [11]	Indeterminate.	Misinterpreted sauropod bone.	Other more plausible Stegosaur material is known from Cretaceous India.	Kallamedu formation
Sauropoda	Sauropoda indet. [5]		"Scant remains".
Stegosauria	Stegosauria indet. [5]
Theropoda	Theropoda indet. [5]		"Scant remains".
Theropoda [12]	indet.		A Theropod.	Kallankurichchi formation
? Titanosaurus [12]	T. indicus		A dubious genus of titanosaurian sauropod.	Kallakurichi Formation	Titanosaurus
Megaloolithus [13]	M. cylindricus	Fossilised eggs.	A Sauropod Oogenus.	Kallakurichi Formation	Sanajeh fossil The holotype of Sanajeh preserved with Megaloolithus
Stegosauridae [12]	Stegosauridae indet			A Stegosaurid.	Kallakurichi Formation

Molluscs from the Ariyalaur group
Genus	Species	Material	Notes	Member	Images
Inoceramus [5]	I. sp.			Sillakkudi formation
Karapadites [5]	K. karapadense			Sillakkudi formation
Inoceramus [14]	I. bulbus		A clam.	Kallakurichi formation
	I. tamulicus			Kallakurichi formation
Pycnodonta [14]	P. vesicularis		A clam.	Kallakurichi formation
Ostrea (Alectryonia) [14]	sp.		A clam.	Kallakurichi formation
Anisomyon [14]	A. indicus		A snail.	Kallakurichi formation

Foraminiferas from the Ariyalaur group
Genus		Species	Material	Notes	Images
Globotruncana	G. arca [5]			Sillakkudi formation
	G. ventricosa [5]			Sillakkudi formation
	G. elevata [5]			Sillakkudi formation

Sea Urchins from the Ariyalaur group
Genus	Species	Material	Member	Notes	Images
Hemipneustes	H. compressus [15]		Kallakurichi Formation

Rhynchonellatans from the Ariyalaur group
Genus	Species	Material	Notes	Member	Images
Rectithyris	R. subdepressa [14]			Kallakurichi Formation
Rhynchonella	R. sp. [14]			Kallakurichi Formation

Brachiopods from the Ariyalaur group
Genus	Species	Material	Notes	Member	Images
Gyrodina	G. globosa [14]			Kallakurichi Formation
Neobulimina	N. sp. [14]			Kallakurichi Formation

Arthropods from the Ariyalur group
Genus	Species	Material	Notes	Member	Images
Thalassinoides	T. sp. [5]		An ichnofossil made by decapod crustaceans, or fish	Ottakovil Formation
Ophiomorpha	O. sp. [5]		Made by burrowing arthropods	Ottakovil Formation

References

1. Bakkiaraj, D.; Nagendra, R.; Nagarajan, R.; Armstrong-Altrin, John S. (2010). "Geochemistry of sandstones from the Upper Cretaceous Sillakkudi Formation, Cauvery Basin, southern India: Implication for provenance". Journal of the Geological Society of India. 76 (5): 453–467. Bibcode:2010JGSI...76..453B. doi:10.1007/s12594-010-0128-3. hdl: 20.500.11937/18718 . ISSN   0016-7622.
2. Banerji, Ranjit K. (1966-06-01). "The Genus Globotruncana and Biostratigraphy of the Lower Ariyalur Stage (upper Cretaceous) of Vridhachalam, South India" . Journal of the Geological Society of India. 7 (1): 51–69. doi:10.17491/jgsi/1966/070111. ISSN   0974-6889.
3. Goswami, A.; Prasad, G. V. R.; Verma, O.; Flynn, J. J.; Benson, R. B. J. (2013). "A troodontid dinosaur from the latest Cretaceous of India". Nature Communications. 4: 1703. Bibcode:2013NatCo...4.1703G. doi: 10.1038/ncomms2716 . PMID   23591870.
4. Yadagiri, P. and Ayyasami, K. (1987). "A carnosaurian dinosaur from the Kallamedu Formation (Maestrichtian horizon), Tamilnadu." In M.V.A. Sastry, V.V. Sastry, C.G.K. Ramanujam, H.M. Kapoor, B.R. Jagannatha Rao, P.P. Satsangi, and U.B. Mathur (eds.), Three Decades of Development in Palaeontology and Stratigraphy in India. Volume 1. Precambrian to Mesozoic. Geological Society of India Special Publication, 11(1): 523–528.
5. Pal, Saurabh; Ayyasami, Krishnan (May 2022). "The lost titan of Cauvery" . Geology Today. 38 (3): 112–116. Bibcode:2022GeolT..38..112P. doi:10.1111/gto.12390. ISSN   0266-6979.
6. R. Lydekker. (1877). Notices of new and other Vertebrata from Indian Tertiary and Secondary rocks. Records of the Geological Survey of India 10(1):30–43
7. C. R. Narayana Rao and L. Rama Rao. 1930. The limb bones of a sauropodous dinosaur. Proceedings of the Indian Science Congress, Allahabad17:330.
8. Dhiman, Harsha; Prasad, Guntupalli V. R.; Goswami, Anjali (2018). "Parataxonomy and palaeobiogeographic significance of dinosaur eggshell fragments from the Upper Cretaceous strata of the Cauvery Basin, South India". Historical Biology: 1–13. doi:10.1080/08912963.2018.1450408. S2CID   89969203.
9. Matley, 1929. "The Cretaceous Dinosaurs of the Trichinopoly district and the rocks associated with them". Records of the Geological Survey of India. Vol. 61 (4):337-349.
10. C. R. Narayana Rao and L. Rama Rao. 1930. Some dinosaurian vertebrae. Proceedings of the Indian Science Congress, Allahabad17:329.
11. Peter M. Galton; Krishnan Ayyasami (2017). "Purported latest bone of a plated dinosaur (Ornithischia: Stegosauria), a "dermal plate" from the Maastrichtian (Upper Cretaceous) of southern India". Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 285 (1): 91–96. doi:10.1127/njgpa/2017/0671.
12. Weishampel, et al. (2004). The Dinosauria. Second Edition. p. 680.
13. Kohring et al., 1996^{[ incomplete short citation ]}
14. Ayyasami, 1989^{[ incomplete short citation ]}
15. Aziz & Badve, 1990^{[ incomplete short citation ]}