Face to face: a child killer and its prey
From Jonathan Clayton in Johannesburg, Times Online, 13.01.06
THE African crowned eagle was found guilty yesterday of the murder about two to three million years ago of arguably the most important human ancestor found.
The mystery of how the Taung child, the continent’s first hominid discovery, met its end, aged 3½, has puzzled scientists for decades and could throw important new light on the theory of human evolution.
“This is the end of an 80-year-old murder mystery . . . We have proved conclusively and beyond a reasonable doubt, which would be accepted in a court of law, that the African crowned eagle was the killer,” Lee Berger, an American palaeontologist, said.
The end of the mystery “gives us real insight into the past lives of these human ancestors,” he said. “It shows it was not only big cats, but also these creatures from the air — aerial bombardment if you will — that our ancestors had to be afraid of. These were the stressors and stresses that grew and shaped the human mind and formed our behaviour today.”
In 1924 the discovery of the half-ape, half-man fossilised skull about 300 miles (480 kilometres) northwest of Johannesburg overturned the view that humans originated in Eurasia and focused the search for the “cradle of humanity” on Africa.
Announcing the verdict, Professor Berger, a reader in palaeoanthropology at Wits University in Johannesburg, said new evidence showed that the child was not killed by leopards or sabre-toothed cats, the previous suspects.
He said “small punctures and keyhole slots” inside the eye sockets and brain area could not have been made by such large predators.
“Carnivores cannot create that sort of damage,” he told a press conference in the margins of an international conference on the origins of man. “This child was killed by a single blow of a 14cm long talon into the brain . . . It was later disembowelled. The eagle would have used its beak to eat out the eyes and the brain — some of the most nutritious parts — and created these marks.”
The Taung child was discovered by Raymond Dart, a British professor who had recently arrived to take up a new post in South Africa. He published a paper in Nature saying that the child, a specimen of the human ancestor species Australopithecus africanus, was the famed “missing link” between man and ape.
The bold claim was widely dismissed at the time, but subsequently other, older hominids, such as Lucy, believed to be more than three million years old, were found in the Great Rift Valley that snakes across the continent from South Africa through Kenya and Tanzania to Ethiopia.
Professor Berger and Ron Clarke, a fellow palaeontologist, first mooted the theory that the killer was a predatory bird similar to today’s African crowned eagle about ten years ago.
“The one big problem was the lack of multiple areas of damage that could be linked to a bird of prey,” Professor Berger said. “We had one little flap of bone on the top of the skull that looked like some of the damage we see made by eagles and nothing else. It was the ultimate two-million-year-old cold case!”
Five months ago researchers from Ohio State University submitted what Professor Berger called the most comprehensive study to date of eagle damage on bones. Asked to review the paper for the American Journal of Physical Anthropology, Professor Berger realised that he had stumbled upon his own missing link.
The study on primate remains from modern-day crowned eagle nests in the Tai forest in Ivory Coast showed that raptors routinely hunt primates much larger than themselves by swooping down at speed and piercing their skulls with their back talons.
The Ohio State paper also identified key features that distinguished damage caused by eagles from that of other predators. They include the flaps of depressed bone on top of the skull caused by the birds’ talons and keyhole-shaped cuts on the side made by their beaks.
They also identified puncture marks and ragged incisions in the base of the eye sockets, made when eagles rip out the eyes of dead monkeys with their talons and beaks.
Professor Berger returned to the skull of the Taung child and noticed a tiny hole and jagged tears at the base of the eye sockets. “I couldn’t believe my eyes, as thousands of scientists, including myself, had overlooked this critical damage. I felt a little bit of an idiot,” he said.
Professor Berger’s research, which has already been reviewed and accepted by experts in the field, is due to be published in the February edition of the prestigious American Journal of Physical Anthropology.
ORIGIN OF MAN
# Human remains from 3.2 million years ago were discovered in Ethiopia in 1974. The early human, or Australopithecus afarensis, Lucy, was named after the Beatles song Lucy in the Sky with Diamonds
# Last year Ethiopian and US scientists claimed to have discovered fossils of human ancestors from about 3.8 to 4 million years ago. The ankle bone seemed to show that the individual walked upright
# The Laetoli footprints, discovered in 1978 in Tanzania, are estimated to be 3.7 million years old. The footprints are almost identical to those of modern humans
# In 1959 a British the British paleoanthropologist Mary Leakey discovered a 1.8 million-year-old skull in the Olduvai Gorge, northern Tanzania. It was the first Australopithecus boisei skull found
# In 1984 a skeleton of a boy — homo erectus — who died 1.6 million years ago was discovered near Lake Turkana in Kenya
# posted by Unknown : 10:51 PM
