Astonishing Skull Unearthed in Africa
July 10, 2002
By Ivan Noble
Photo: Toumai: Oldest ancestor? Image: MPFT
This is a picture of the recently unearthed human-like skull which is being described as the most important find of its type in living memory.
It's the most important find in living memory Henry Gee, Nature
It was found in the desert in Chad by an international team and is thought to be approximately seven million years old.
"I knew I would one day find it... I've been looking for 25 years," said Michel Brunet of the University of Poitiers, France.
Scientists say it is the most important discovery in the search for the origins of humankind since the first Australopithecus "ape-man" remains were found in Africa in the 1920s.
The newly discovered skull finally puts to rest any idea that there might be a single "missing link" between humans and chimpanzees, they say.
Analysis of the ancient find is not yet complete, but already it is clear that it has an apparently puzzling combination of modern and ancient features.
Henry Gee, senior editor at the scientific journal Nature, said that the fossil makes it clear how messy the process of evolution has been.
"It shows us there wasn't a nice steady progression from ancient hominids to what we are today," he told BBC News Online.
"It's the most important find in living memory, the most important since the australopithecines in the 1920s.
"It's amazing to find such a wonderful skull that's so old," he said.
What is the skull's significance?
The skull is so old that it comes from a time when the creatures which were to become modern humans had not long diverged from the line that would become chimpanzees.
There were very few of these creatures around relative to the number of people in the world today, and only a tiny percentage of them were ever fossilised.
So despite all the false starts, failed experiments and ultimate winners produced by evolution, the evidence for what went on between 10 and five million years ago is very scarce.
Grandparent, great uncle, great aunt?
There will be plenty of debate about where the Chad skull fits into the incomplete and sketchy picture researchers have drawn for the origins of the human species.
Photo: The hominid's jaw was found later
"A find like this does make us question the trees people have built up of human evolution," Chris Stringer of the Natural History Museum told the BBC.
Sahelanthropus tchadensis, as the find has been named, may turn out to be a direct human ancestor or it may prove to be a member of a side branch of our family tree.
The team which found the skull believes it is that of a male, but even that is not 100% clear.
"They've called it a male individual, based on the strong brow ridge, but it's equally possible it's a female," said Professor Stringer.
Future finds may make the whole picture of human evolution clearer.
"We've got to be ready for shocks and surprises to come," he said.
The Sahelanthropus has been nicknamed Toumai, a name often given to children born in the dry season in Chad.
"This is regarded by some as the most significant find in living memory" Dr Henry Gee, Nature magazine
"It came out of the ground entire, normally one finds bits and pieces"
What the experts say
The scientist who led the team which found the Toumai skull has described his delight.
"It's a lot of emotion to have in my hand - the beginning of the human lineage," said Michel Brunet of the University of Poitiers, France.
"I have been looking for this for so long. I knew I would one day find it... I've been looking for 25 years," he told reporters in Chad.
Daniel Lieberman of Harvard University, US, one of Brunet's contemporaries to have seen the Chad skull, said its discovery would have the impact of "a small nuclear bomb".
And Henry Gee, senior editor at Nature, which carried full details of the find, had no doubts about its significance:
"Toumai is arguably the most important fossil discovery in living memory, rivalling the discovery of the first 'ape-man' 77 years ago - the find which effectively founded the modern science of palaeoanthropology," he said.
Q&A: The Chad skull find
Professor Chris Stringer at the Natural History Museum in London, UK, said that the discovery of Toumai was "very significant".
Its discovery shows how much evidence has been missing up to now
Chris Stringer: Natural History Museum "First, because of its location in what is now desert, over a thousand miles away from the sites in East Africa that have featured in the search for our origins so far.
"Second, because it is the only relatively complete skull so far discovered in a 'fossil gap' of five million years between the ancestral apes of nine million years ago and the australopithecines, generally regarded as our close relatives, from four million years onwards," he said.
Toumai's discoverer outlines the significance
Sahelanthropus tchadensis, to give Toumai its scientific name, had a mixture of features.
"It had an ape-like brain size and skull shape, combined with a more human-like face and teeth.
"It also sported a remarkably large brow-ridge, more like that of younger human species.
"Its discovery shows how much evidence has been missing up to now," Professor Stringer said.
The number of precursors of modern humans living at the time of Toumai might well be as high as the number of modern ape species alive today.
Researchers would be looking for gorilla and chimpanzee ancestors from Toumai's time, too, he added.