The persistence of these animals in what is today central England is probably an example of 'extinction lag,' whereby small pockets survive even as the species as a whole disappears from the planet.
Credit: Mauricio Anton/PLoS
PARIS: Woolly mammoths survived in Britain until 14,000 years ago, around 6,000 years longer than previously thought, according to a study released today.
The find should settle a raging debate over the extinction of mammoths in Europe, unleashed when fossils from an adult male and four youngsters were found in the central English county of Shropshire in 1986, said author Adrian Lister, of the Natural History Museum in London.
Conventional wisdom has held that mammoths (Mammuthus primigenius) died out in northwestern Europe some 21,000 years ago during a deep freeze called the last glacial maximum. But the new research, published in the Geological Journal, proves that the giant tuskers of prehistory hung on for at least another six millennia.
Better dating
"Our new radiocarbon dating of the Shropshire mammoths shows they returned to Britain and survived until around 14,000 years ago," said Lister, who explained that previous techniques used for dating the fossils were not very accurate.
The giant mammals flourished during the initial phase of the last Ice Age but, despite their "woolly" coats, could not cope with its bitterest chill. The British mammoths headed south and east towards warmer climes, crossing a land bridge to continental Europe when sea levels were up to 100 m below where they are now.
The mammoths came back when the glacial maximum eased and then survived until the end of the ice age, when encroaching forests gradually destroyed their food supply, said Lister.
"Mammoths were basically a grass-eating animal. During the ice age, the environment across most of Europe was essentially grassland because it was too cold for trees," he explained.
Extinction lag
As it got warmer, trees spread northward and covered the whole of Europe, robbing these animals of their habitat. "Their populations were squeezed down into remnants and then disappeared altogether," said Lister.
The persistence of these animals in what is today central England is probably an example of 'extinction lag,' whereby small pockets survive even as the species as a whole disappears from the planet, he said.
Other giant mammals that vanished in Europe as the last ice age relented and human populations began to expand include the woolly rhinoceros, horses, giant deer and bison.
Similar die-outs of megafauna occurred around the world about the same time, prompting scientists to ask which was more to blame, the shifting climate or human predators. Lister said human hunters may have finished off the surviving pockets of mammoths but were probably not the main cause of their demise.
