New Delhi: Researchers have discovered nearly 500 finger and toe bones belonging to primates, some half the size of a mouse, that lived about 45 million years ago in what is now China, offering evidence that early human ancestors came from Asia.
During the mid-Eocene period, about 45 million years ago, they lived in tree canopies and fed on fruit and insects in a tropical rainforest in what is now China, according to a study published online in the Journal of Human Evolution.
Representing nine different taxonomic families of primates and as many as 25 species, the specimens include numerous fossils attributed to Eosimias, the very first anthropoid known to date, and three fossils attributed to a new and much more advanced anthropoid.
The anthropoid lineage would later include monkeys, apes and humans.
"The new study provides further evidence that early anthropoids were minuscule creatures, the size of a mouse or smaller," said study co-author Daniel Gebo, Professor at Northern Illinois University in the US.
"It also adds to the evidence pointing toward Asia as the initial continent for primate evolution. While apes and fossil humans do come from Africa, their ancestors came from Asia," Gebo said.
Many of the smaller fossils are between one and two millimetres in length, and the animals would have ranged in full body size from 10 to 1,000 grams, the study said.
The newly described fossils were recovered from a commercial quarry near the village of Shanghuang in the southern Jiangsu province of China, about 100 miles west of Shanghai.
"The fossils are extraordinarily small, but in terms of quantity this is the largest single assemblage of fossil primate finger and toe specimens ever recorded," Gebo said.