A mysterious subspecies of gorilla has been dispatched back into the mists of legend by a coil of DNA. After a century of speculation, it seems that Gorilla gorilla uellensis never existed.
Genetic analysis of remains of what some thought might be the fourth subspecies of the giant ape revealed that they were of a population already known to science.
The sole evidence for the existence of the gorillas -three skulls and a jawbone -was presented to the Royal Museum for Central Africa in Tervuren, Belgium, by a colonial army officer in 1898. They had supposedly come from an area near the Uele River in the Bili forest, in what is today the Democratic Republic of Congo.
Palaeontologist Henri Schouteden later suggested the animals were sufficiently different from those already known to constitute a new subspecies. But repeated attempts to find uellensis in the wild, most recently by Swiss-born wildlife photographer Karl Ammann, have met with failure.
Now scientists at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have suggested that it has not been found because it does not exist. The team found that genetic sequences from DNA recovered from the teeth of one of the Tervuren specimens were compatible with western lowland gorillas, casting doubt on the idea that the apes originated in northern Congo.
Linda Vigilant, a research scientist in the Max Planck team, which is led by Michael Hofreiter, an expert on ancient DNA, said the evidence published in the latest issue of the American Journal of Physical Anthropology was fairly conclusive. She added: "This is the end for Gorilla gorilla uellensis ."
Mr Ammann, who is still hunting for an elusive ape in the Bili forest, accepted that it was unlikely that a population of an unknown gorilla was out there. But he said he had found evidence of a previously unknown type of large chimpanzee that seemed to share some behaviours with gorillas such as living in ground nests.
"I have little doubt we are dealing with a chimp population that seems to have interesting new cultural traits and might turn out to have some morphological characteristic that would make these chimps special," he said.
Hair and faecal samples taken by Mr Ammann from the apes' nests have been analysed in several laboratories. Preliminary results confirm that they come from chimps.