Crocodiles, turtles and fish were eaten by early humans almost 2 million years ago, archaeologists have found.

This is the oldest evidence for a diet containing aquatic animals, the study's researchers have claimed. The boffins also added that the nutrients they provided could have fuelled the evolution of our large human brains.

Co-author and paleoanthropologist Dr. Richmond said, "These aquatic foods are really important sources of the long-chain polyunsaturated fatty acids and docosahexaenoic acid that are so critical to human brain growth. Finding these foods in the diets of our early ancestors suggests they may have helped to lift constraints on brain size and fuel the evolution of a larger brain."

The discovery of such a diverse animal diet is important because early human brain size increased dramatically after two million years ago.

It has been reported that growing a large brain requires an enormous investment in calories and nutrients and places considerable costs on the mother and developing infant. Anthropologists have long considered meat in the diet as key to the evolution of a larger brain. However, until now, there was no evidence that human ancestors this long ago had incorporated into their diets animal foods, from lakes and rivers, rich in brain nutrients.

The report further said that a team of scientists from Kenya, the United States, the U. K., Australia and South Africa discovered a 1.95 million year-old site in northwestern Kenya in 2004. Preservation of the excavated site was so remarkable that the team was able to develop a detailed reconstruction of the environment. Over four years, the scientists excavated literally thousands of fossilized bones and stone tools, and were able to determine that at least
10 individual animals, and perhaps many more, were butchered by early humans at this site. (With Inputs from Agencies)