- It's not certain whether this is a direct human ancestor or close relative.
- The skeleton was found at the Cradle of Humankind in South Africa, the oldest ongoing paleontological dig in the world.
South African scientists said Thursday they had uncovered the most complete skeleton yet of an ancient relative of man, hidden in a rock excavated from an archaeological site three years ago.
The remains of a juvenile hominid skeleton, of the Australopithecus (southern ape) sediba species, constitute the "most complete early human ancestor skeleton ever discovered," according to University of Witwatersrand palaeontologist Lee Berger.
"We have discovered parts of a jaw and critical aspects of the body including what appear to be a complete femur (thigh bone), ribs, vertebrae and other important limb elements, some never before seen in such completeness in the human fossil record," said Berger, a lead professor in the finding.
The latest discovery of what is thought to be around two million years old, was made in a three-foot (one meter) wide rock that lay unnoticed for years in a laboratory until a technician noticed a tooth sticking out of the black stone last month.
The technician, Justin Mukanka, said: "I was lifting the block up, I just realized that there is a tooth."
It was then scanned to reveal significant parts of an A. sediba skeleton, dubbed Karabo, whose other other parts were first discovered in 2009. Parts of three other skeletons were discovered in 2008 in the world-famous Cradle of Humankind site north of Johannesburg.
It is not certain whether the species, which had long arms, a small brain and a thumb possibly used for precision gripping, was a direct ancestor of humans' genus, Homo, or simply a close relative.
"It appears that we now have some of the most critical and complete remains of the skeleton," said Berger.
Other team members were equally enthusiastic.
"It's like putting together the pieces of a puzzle," university laboratory manager Bonita De Klerk told AFP.
The skeleton of what has been dubbed Karabo and is thought to date back to around two million years old, would have been aged between nine and 13 years when the upright-walking tree climber died.
Remains of four A. sediba skeletons have been discovered in South Africa's Malapa cave, 30 miles (50 kilometers) north of Johannesburg, since 2008. The individuals are believed to have fallen into a pit in the cave and died.
The sediba fossils are arguably the most complete remains of any hominids found and are possibly one of the most significant palaeoanthropological discoveries in recent time.
The Cradle of Humankind, now a World Heritage Site, is the oldest continuous paleontological dig in the world.
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The university also announced it would open up the process of exploring and uncovering fossil remains to the public and stream it online in real time.
A special laboratory studio will be built at the Cradle of Humankind.
"The public will be able to participate fully in live science and future discoveries as they occur in real time -- an unprecedented moment in palaeoanthropology," said Berger.
The lab and the virtual infrastructure are expected to be built within a year, according to Qedani Mahlangu, a regional minister of economic development.
The university is in talks with Shanghai Science and Technology Museum in China, Britain's Natural History Museum and the Smithsonian in the United States to set up virtual outposts for the live science project.