The researchers hope that this finding will draw more attention to the region and more studies will be carried out in the future.

Tireless fossil hunting under the scorching heat of the Kutch basin, Gujarat proved fruitful — palaeontologists have unearthed a fossilised upper jaw (maxilla). Further studies showed that the fossil find was highly significant: it is the oldest and the only known ape fossil discovered in peninsular India.

Dr. Ansuya Bhandari from Birbal Sahni Institute, Lucknow stumbled upon the jaw in 2011 during a field survey with a group of palaeontologists from the Wadia Institute of Himalayan Geology, Dehradun and IIT Roorkee.

The researchers concluded that the upper jaw belonged to an adult ape (hominoid family), belonging to the genus Sivapithecus and lived about 11-10.8 million years ago (Miocene). The oldest found remains of these apes are dated at about 12.7 million years in Indo-Pakistan and the youngest at about 8.6 million years.

“Fossils of the Sivapithecus genus have been previously unearthed near the Siwalik hill range, spreading across Pakistan, Churia Hills in Nepal and around the Himalayas [Jammu & Kashmir and Himachal Pradesh]. Now this finding, almost 1,000 km south from the previous finds has increased the geographic range of the genus” says Dr. Ansuya Bhandari from the Birbal Sahni Institute and first author of the paper recently published in PLOS ONE. “It also fills a time-window of approximately 11 million years in the evolutionary history of hominoid remains in India.”

She also explains that researchers now believe that Sivapithecus is either more close to the modern orangutan of Southeast Asia or an ape that is part of an early radiation of fossil hominoids — the great apes, the chimps, gorillas and orangutans and also humans.

Researchers from Duke University, U.S. carried out the X-ray CT scans. The researchers note that as the unearthed jaw had a lot of iron in it due to its deposition in an iron-rich ancient soil, the radiation was not able to penetrate very deep into the specimen, thus preventing better analysis. They hope that this finding will draw more attention to the region and more studies will be carried out in the future.

By comparing the fossil with other available data on Sivapithecus genus, the authors speculate that the identified jaw could belong to a large-sized ape, attributed to one of the two species of Sivapithecus, hysudricus or sivalensis. More, better preserved and unfragmented specimens are required to identify the exact species.

“Kutch is a paradise for fossils. Many associated mammal fossils belonging to the Miocene age have been discovered here in the past, including whales and sea cows. The new discovery will help us understand in detail the evolution of great apes,” says Prof. Sunil Bajpai from the Department of Earth Sciences at IIT, Roorkee and former director of Birbal Sahni Institute. He is one of the authors of the paper.