SOURCE: Telegraph (UK) (4-8-10)
The two partial skeletons, found in a South African cave, are a previously unknown species, say the team who discovered them.
They contain elements of both the apelike hominids from which man is believed to be descended, known as Australopithecus, and modern humans.
Experts described the find as “rare” and “truly amazing" and said that they could fill in some of the gaps in scientific knowledge surrounding human evolution.
One of the fossils is of a male child, believed to be around eight or nine years old, while the other is of an adult female, thought to be in her late 20s or early 30s.
Found near the Sterkfontein caves near Johannesburg, where other remains have been uncovered, they are believed to be between 1.95 million and 1.78 million years old.
They reveal a species with long legs and a sophisticated hip bone, making them able to stride like humans, and researchers believe that they could have signified the dawn of a more energy-efficient way of walking.
But they also still had the strong hands and long arms more reminiscent of an ape.
Both were just over four foot tall, with the female weighing in around five stone and the child around four stone.
Although small their brains appear to have been more advanced than other similar species.
Two more skeletons have been discovered since the original find in 2008, but the team behind the find refused to reveal any details about them.
The new species has been named Australopithecus sediba, which means “southern ape, wellspring”.
Prof Lee Berger, from South Africa's University of Witwatersrand, who led the team, said: “These fossils give us an extraordinarily detailed look into a new chapter of human evolution and provide a window into a critical period when hominids made the committed change from dependency on life in the trees to life on the ground."
"Australopithecus sediba appears to present a mosaic of features demonstrating an animal comfortable in both worlds."
Dr Robyn Pickering, from the University of Melbourne, who was part of the team who dated the remains, said: “It has never been clear where our own genus Homo came from – this new discovery, Australopithecus sediba could answer these questions.
“Knowing how old these early human (hominin) fossils are, is critical to our knowledge of where this newly found species fits into our family tree.”
Dr Darren Curnoe, a specialist in human evolution at the University of New South Wales, who was not involved in the research, insisted that the fossils were not ancestors of modern man.
“The discovery of one, let alone two, partial skeletons of the fossil relatives of humans is a rare and truly amazing thing.
“It also adds yet another branch to our evolutionary tree and confirms an emerging picture of nature’s grand experiment with human-like apes, living humans the sole survivor of evolutionary tinkering.”
But he added: “Australopithecus sediba is the wrong species, in the wrong place, and at the wrong time.
“It is way too primitive to be the ancestor of the human genus Homo, one of our direct ancestors.”
The findings are published in the journal Science.