For the past 15 years, a group of scientists have been looking inside a cavernous coal mine at Surat in Gujarat to look for clues about the origins of India’s animal life.
Last year, the group found fossils that suggested that the ancestors of horses and rhinos originated in India when it was an island.
The team was back again at the mine from March 11 to 22, looking for more animal remains that could establish the origin and diversification of India’s first mammals. The group comprised scientists, professors and PhD students.
Against the backdrop of noisy mining trucks, the researchers from Indian as well as foreign institutes were looking in the fossil-bearing layers set above 10 to 12 metres of coal-rich deposits for origins of India’s present day mammals and primates.
Comfortably squatting at the edge of an operational open-pit mine about 50 feet from the mine floor under the harsh mid-March sun, professor Kenneth Rose and his team made their first visit of this year looking for fossils of primates in the 30-50 cms thick layer of sediments of an active mine. (The name of the mine has been withheld on the team’s request.) A primate is any mammal of the group that includes lemurs, lorises, tarsiers, monkeys, apes and humans.
“We are now looking for additional primate fossils and other vertebrates that may add new information to what we have found so far. This will help in understanding the early origins of animal groups and their diversification as well as the fauna of India,” said Rose, professor in the Centre for Functional Anatomy and Evolution at the US-based Johns Hopkins University School of Medicine, as he examined a fossil fish palate through a small hand lens hanging around his neck.
In November last year, the team reported on 200 fossils that dated back to 54.5 million from the Vastan lignite mine. The findings, results of which were published in a paper in Nature Communications, suggested that the ancestor of horses and rhinoceros – animal called Cambaytherium thewissi – originated in India while it was still an island headed swiftly for collision with Asia.
“We are pleased to find several primate jaws and bones since we were not at all sure that we would find them. Our success in finding them should help in getting refunded to return to Gujarat,” said Rose.
The work has been supported by the National Geographic Society and The Leakey Foundation.
The team, since 2001 has been excavating animal fossils in Gujarat dating back about 55-53 million years – also called the Eocene period – to test the theory that some mammal groups originated in India. Eocene refers to the appearance and diversification of many modern groups of organisms, especially mammals and molluscs.
Battling harsh conditions, with day temperatures soaring above 40 degrees, the team looked for fossils almost eight hours every day. Not leaving anything to chance, about 700 to 800kg of sediments comprising fossils as tiny as one millimeter have been screen-washed — similar to a filtration process — at the mining site.
“Three of us have carried around 10kg each of residue containing these fossils back to our laboratories. These will be examined under the microscope which will take months as one cannot look under the microscope beyond 20 minutes at a given time,” said Kishore Kumar, scientist from Wadia Institute of Himalayan Geology, Dehradun.
(Photos: Snehal Rebello And Thierry Smith)