SALEM: Scholars of a university here claim to have stumbled on what could be the largest dinosaur-nesting site in India, in the Cauvery river basin near Ariyalur. They want the area declared a nationally significant geological site to protect it and enable future researchers to explore what they say is an inexhaustible storehouse of information.
Dr Muthuvairavasamy Ramkumar, the principal investigator who led a team of four scholars of Periyar University’s Department of Geology at Salem, said: “We documented the occurrence of dinosaur nesting site in an area of 2 sq km. It may perhaps qualify to be the largest ever known site in India in terms of area, presence of large number of eggs, egg clusters, nesting pits and repetitive occurrence of these features in various layers of the earth (stratigraphic levels).”
The research is part of a UGC sponsored project called ECONDIA.
“It is for the first time that a nesting site has been found in the Cauvery basin. The site was found among sedimentary rocks between Coleroorn and Vellar rivers north east of Ariyalur. From the physical characteristics of the straigraphic layers, conclusive direct evidence affirming the link between Deccan volcanism and resulting environmental deterioration during the later part of Cretaceous era (140 to 65 million years, which witnessed the extinction of dinosaurs and advent of flowering plants and modern insects) that might have contributed towards faunal destruction, is being recorded for the first time,” he added.
The discovery has ramifications in the environmental models postulated for the extinction of various species at the end of the Cretaceous period, including that of giant lizards, fishes and micro-organisms. In contrast to the existing theories that the end of the Cretaceous era was sudden and widespread due to meteoric impact, the ECONDIA project has found path-breaking evidence that points to a multi-casual, staggered progress towards extinction of the Paleolithic life says Dr Ramkumar.
Physical observation of occurrences of red coloured silty shale or weathered volcanic ash recorded from core samples 5 km to 15 km away from the nesting site is a direct evidence of the impact of Deccan volcanism. The study throws up the question whether the resulting environmental stress caused infertility, which caused the extinction of dinosaurs.
Considering the number of nests and eggs in them, the Kallamedu formation (the discovered site) of the Cauvery basin might have been a thriving place for dinosaurs. This is contrary to the prevailing view that there might have been a few dinosaurs, fragmentary bone remains of which are scattered scarcely in this formation. More detailed studies are needed, for which the site must be protected from vandalism, he said.