IDA WAS just 58cm (23inches) long and nine-months-old when she died 47 million years ago, but scientists are confident the cat-like creature is the common ancestor of all primates.
Found in a quarry near Frankfurt, Germans have already adopted “Auntie Ida” as one of their own, an ancient ancestor who may be the long-sought “missing link” between humans and other primates.
“It’s a very important finding for the understanding of early human evolution because this is the only complete primate that’s this old,” said Prof Jørn Hurum, who analysed the fossil, at its presentation in New York’s Museum of Natural History on Tuesday.
A female, cat-like creature with four legs and a tail, the fossil is 95 per cent complete and 20 times older than anything previously found.
“Everything else is really small pieces of jaws, maybe single teeth and single bones,” said Prof Hurum. “So this will set a new landmark for the understanding of the early evolution of primates.”
The first primates are believed to have evolved about 55 million years ago. Sometime between 40 to 50 million years ago, a division took place with humans, apes and monkeys splitting from a second group that includes lemurs.
Prof Hurum is anxious to play down “missing link” speculation – there are many blank spots in millions of years of evolution, making it difficult to pinpoint from where exactly humans emerged.
But, considering Ida was alive at sometime in this period, he calls his specimen “as good as it gets, really”.
At first glance Ida – officially called Darwinius masillae in honour of evolution theorist Charles Darwin – resembles the lemurs that live today in Madagascar.
Scientists suggest that Ida’s parents were probably about half a metre long, weighing about one kilogram including a long tail.
But a closer look reveals that certain lemur characteristics are missing, such as claws and grown-together teeth.
At the same time, important links to humans can be found in Ida’s limbs, such as a talus bone in her ankle which resembles a human bone in shape.
The similarity does not end there.
“Ida already has a grasping hand over an opposable thumb. And she has flat nails like us today,” said Dr Jens Franzen of the Senckenberg Research Institute in Frankfurt, also involved in the analysis.
“So on the first look already you get the idea this is something not too far from ourselves. For me this is the eighth wonder of the world.”
Ida is not a new discovery: she was uncovered back in 1983 by an amateur fossil hunter in what, at the time of her death, was a rain forest.
It was transformed into what is known today as the “Messel mine” around 50 million years ago by a volcano. Scientists believe many animals drowned in the landscape of water-filled craters, their bodies carried to the bottom and fossilised in sedimentary rock.
Ida is a particularly well-preserved specimen, her body pressed between layers of stone known as oil shale.
The area became an open-pit mine at the end of the 19th century and the shale stripped away until the 1970s.
Plans to turn the area into a giant dump were stopped by local residents in the 1980s. In 1991, the mine was purchased by the local government and declared a Unesco world heritage site four years later.
The site has turned up extraordinary specimens, including early relations of crocodiles, bats and snakes, as well as an evolutionary series of early horses.
Ida only came to light when her finder offered her for sale two years ago to the Oslo Natural History museum.
Norwegian palaeontologist Hurum headed the analysis team. Using computer tomography, he discovered the remains of Ida’s fur and the contents of her stomach: a last meal of fruit, seeds and leaves.
His team’s findings were published in the Public Library of Science journal PLoS ONE and presented in New York.
A television documentary about the discovery will be screened next Tuesday, narrated by Sir David Attenborough.
“This little creature is going to show us our connection with the rest of all the mammals,” he said to the ABC network in the US.
“Now people can say, okay you say we’re primates, like monkeys and apes, and that we came from simple generalised mammals. Show us the link; the link they would have said until now is missing. Well it is now no longer missing.”