Northeast of Kallamedu, microsite yielding troodontid tooth (Cretaceous of India)

Where: Tamil Nadu, India (11.2° N, 79.0° E: paleocoordinates 34.0° S, 56.9° E)

• coordinate estimated from map

• small collection-level geographic resolution

When: Kallamedu Formation (Ariyalur Group), Late/Upper Maastrichtian (70.6 - 66.0 Ma)

• The focus of this study is on the youngest of these units, the Ariyalur Group, which is extensively exposed to the east and northeast of the town of Ariyalur. The dinosaurian tooth described here was recovered from screenwashing of 300 kg of sandy clays from the Kallamedu Formation, which forms the uppermost beds of the Ariyalur Group and has been assigned a Late Maastrichtian age based on planktonic foraminferans

• bed-level stratigraphic resolution

Environment/lithology: lacustrine - small; sandy claystone

• Interpreted as a freshwater pond deposit

•The Cauvery Basin is a large northeast-southwest trending structure that formed during the Late Jurassic–Early Cretaceous rifting of India and Australia-Antarctica28

• Sandy clays from the Kallamedu Formation

Size class: mesofossils

Collected by G. V. R. Prasad, A. Goswami and Department of Geology at National College, Tiruchirapalli in 2007, 2009 and 2010

Collection methods: surface (in situ), mechanical, sieve,

• DUGF, Delhi University, Geology Department, Fossil Catalogue, Delhi, India

•Surface prospecting was undertaken in a large exposure of the Kallamedu Formation (Fig. 1) during expeditions in 2007, 2009 and 2010, which revealed a large concentration of highly fragmentary large bones that likely represent dinosaur taxa and have been previously identified as titanosaur sauropods. In addition, microsites with concentrations of ganoid fish scales, turtle carapace fragments, and abelisaurid theropod and crocodilian teeth were identified during surface prospecting. The specimen described here was recovered during screenwashing of material gathered from one such microsite

Primary reference: A. Goswami, G. V. R. Prasad, O. Verma, J. J. Flynn, and R. B. J. Benson. 2013. A troodontid dinosaur from the latest Cretaceous of India. Nature Communications 4:1-5 [P. Mannion/J. Tennant]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 143250: authorized by Roger Benson, entered by Roger Benson on 21.04.2013

Creative Commons license: CC BY (attribution)

Taxonomic list

Reptilia
 Avetheropoda - Troodontidae
Troodontidae indet. Gilmore 1924 coelurosaur
One isolated tooth (DUGF/52)