A fossilised tooth found in Vastan, Gujarat

New Delhi, Aug. 10: Four tiny fossilised teeth found by Indian scientists in a lignite coal mine in Vastan, Gujarat, have pushed back the common ancestry of modern monkeys, apes and humans by about 10 million years.

The Indian scientists and their collaborators in the US have reported the discovery of fossilised teeth that belonged to an anthropoid — an ancestral primate — that lived about 54 million years ago.

“The teeth come from a creature very close to the root of the lineage that eventually gave rise to modern monkeys, apes and humans,” said Sunil Bajpai, associate professor at the Indian Institute of Technology, Roorkee, and head of the research team.

Bajpai has spent several years exploring the Vastan mine, a giant treasure house of animal fossils, a two-hour drive from Surat.

The scientists have named the fossil Anthrasimiasis gujaratensis, the first word combining Greek for coal and Latin for monkey.

Scientists cannot yet say what it looked like in the absence of fossils from other body parts.

But the size and anatomy of its teeth — about three millimetres in length — point to a small creature that lived on a mixed diet of fruits and insects, much like the modern mouse lemurs found on Madagascar island in the Indian Ocean.

This is the oldest anthropoid fossil from Asia, nearly 10 million years older than a Chinese anthropoid that lived about 45 million years ago. Some scientists believe an anthropoid fossil from a limestone deposit in Morocco is older than Anthrasimiasis, but others dispute that claim.

The researchers said the co-occurrence in India of fossils of three different primate superfamilies — anthropoids, omomyoids, and adapoids — shows India was an important centre for the early diversification of primates.

“The new fossils from India are exciting because they show that the anthropoid lineage is much more ancient than we realised,” said Blythe Williams, associate professor at the Duke University in the US, one of Bajpai’s collaborators.

Anthrasimiasis gujaratensis lived during a geological period when India was in the process of colliding with Asia, long after it broke away from Africa and began its flight towards the northern hemisphere.

“The new discovery clearly highlights the importance of the Indian fossil record in tracing the centre of origin and migration patterns of anthropoids and related primate groups,” Bajpai said.

“The teeth came from a geological layer between 54 and 55 million years old,” said B.N. Tiwari, a team member at the Wadia Institute of Himalayan Geology, Dehra Dun.

“We knew they belonged to an old creature. It turned out to be an ancestral primate,” Tiwari added.

The Indian researchers plan to continue their excavation and analysis of fossils from the Vastan mine.

Its inventory includes fossils of ancestors of rabbits, lizards and birds, including an ancestor of the Great Indian Bustard.