A two million-year-old whodunit has been solved, revealing how our ancestors were hunted by huge birds of prey.
Evidence was published yesterday that one killed the Taung child, an apeman skull famed as one of the most dramatic human evolutionary finds.
The toddler had probably been scooped up by a bird and taken to its nest, where its eyes were ripped out, leaving damage to the eye sockets.
The likely culprit, an African crowned eagle, also known as the crowned hawk-eagle, still circles the skies and large eagles still prey on small primates in Africa.
"Birds used to eat us and in doing so they shaped our behaviour," said Dr Lee Berger, of the University of the Witwatersrand, Johannesburg, who will report his conclusions in the American Journal of Physical Anthropology. "Birds of prey are one of the few things that some modern primates have special calls or alarms for."
The threat from birds may explain other aspects of human evolution, from walking upright, which could present a smaller target to an aerial attacker, to living in groups.
The Taung child was unearthed in South Africa in 1924, providing evidence that the continent was the cradle of humankind. For decades it was believed that the child was the victim of a leopard or a sabre-toothed cat.
Ten years ago, Dr Berger and a colleague suggested that the child, about three or four, was killed by a bird. This remained an educated guess until Dr Berger read a paper which listed bone damage distinguishing kills by birds from those of big cats.
"These critical clues were puncture marks in the base of the eye sockets of primates, made when the eagles ripped the eyes out of the dead monkeys with their talons and beaks," Dr Berger said.
He re-examined the Taung child skull. "I looked into the eyes of the skull. I saw the marks - they were perfect examples of eagle damage."