A second theropod tooth from the Cauvery Basin reaffirms the presence of troodontid dinosaurs in the Cretaceous of India

Fossil remains of the small maniraptoran theropod dinosaur group Troodontidae have so far been documented exclusively from the Laurasian continents, with one exception. A single tooth specimen (DUGF/52), recovered from the Upper Cretaceous Kallamedu Formation in the Cauvery Basin, South India, represents the only known record of this group from Gondwana. Recent field investigations in the same locality have yielded a second, better-preserved troodontid tooth (DUGF/168). This study provides a detailed description of the new specimen and compares both Indian teeth with known troodontid material to clarify their taxonomic affinities. In addition to the qualitative morphological comparisons, quantitative statistical analyses, including principal component analysis (PCA) and discriminant function analysis (DFA), were conducted using seven quantitative variables to support taxonomic assessment. The results reaffirm the previous identification of the specimen DUGF/52 as Troodontidae indet and further assign the new specimen to the same family, showing close morphological resemblance to the North American genus Troodon. The occurrence of this typically Laurasian dinosaur group in the Late Cretaceous deposits of India may reflect either the persistence of a once widespread lineage that became restricted to the Northern Hemisphere following the Laurasia-Gondwana breakup or a later dispersal event from Laurasia to India via Europe and Africa.