Scientists in South Africa, initially tipped off by the accidental find of a 9-year-old boy, announced today that they have discovered a set of fossils that could hold the key to unlocking a mysterious period in human evolution.
The fossils are part of a new species, Australopithecus sediba, which are estimated to be nearly 2 million years old and show similarities to both the southern African ape-man and the earliest humans, such as Lucy and Turkana Boy.
"We have one of the most remarkable records, a female, a male and a juvenile of one specific species, and they are showing a pattern," said Lee Berger, an American paleoanthropologist from the University of Witwatersrand in Johannesburg. "Whether they turn out to be a side component or a direct relative [of human beings] they will be extraordinary."
The scientists have assembled an adult female and male, and a young male they estimate was between 10 and 13 years old.
Like apes, the species have long arms and extremely small craniums, but they also have short powerful hands, an advanced pelvis and long legs that the scientists say could have made them capable of walking and even running -- all human characteristics.
Facial features of the sediba are also more similar to modern-day humans, than the Australopithecus africanus, also known as the "ape-man." A look at the skeleton of the young male reveals a human-seeming nose and small teeth.
The scientists are working to put together an entire facial recreation, which they believe will be possible because of the quality of the fossils, according to Berger.
Before the discovery of the sediba, little was known about the period between the africanus and the homo erectus, also known as the first humans.
"I can't overemphasize how poor the fossil record from this period is," said Berger. "There's a pretty good record 100,000 years before it and about 50,000 to 60,000 years after that."
Berger says this new species offers a big clue as to what was happening in the 100,000 years in between.
Two other fossils have also been discovered in the area and are currently being excavated.
Scientists around the world have praised the discovery, scheduled to be published in a Friday report in the journal Science, as significant.
"This is really a remarkable find," Meave Leakey, a paleontologist from the National Museums of Kenya in Nairobi -- where fossils from some of the earliest humans, including Turkana Boy are located -- told Science magazine.
The story of how Sediba was discovered could be considered remarkable in itself. Using Google Earth, Berger and his team plotted various caves and fossil deposits while looking for new ones in the Cradle of Humankind World Heritage site, just outside of Johannesburg.
Google Earth's satellite and 3-D capabilities provided the technology and the ability to share information with other scientists. Berger and geologist Professor Paul Dirks discovered approximately 130 known cave sites and 20 fossil deposits in the area.
Once the sites were identified, it was time for Berger and his team to begin looking for fossils. But neither he nor his team were responsible for finding the first sediba fossils.
Berger's 9-year-old son Matthew made discovery.