Mar 06, 2013 12:55 PM GMT
Gosse’s group at Dalhousie University used a sophisticated dating technique to show the Ellesmere bone fragments are about 3.5 million years old.
When the scientists put all the pieces together, what emerges is a giant camel about 30 per cent larger than today’s camels, weighing about 900 kilograms and standing about 2.7 metres high at the shoulders.
The camels lived in a boreal forest on Ellesmere dominated by larch trees that provided plenty to eat.
There was 24-hour sunshine in the summer and months of darkness in the snowy winters when the camels grew saggy coats to stay warm and survived on fats stored in their humps.
“It was a really different world then,” says Rybczynski.
But she and her colleagues say the camel and its ancient Arctic world hold important lessons.
Slight changes in the Earth’s orbit are believed to have triggered a global temperature rise of two to three degrees about 3.5 million years ago. Due to poorly understood feedback mechanisms in the climate system, the warming was greatly amplified in the Arctic with temperatures on Ellesmere rising 14 to 22 C, allowing the forests — and camels — to move north.
As temperatures rose and Arctic glaciers and ice melted, Gosse says the Northwest Passage and channels around Canada’s Arctic islands were filled with sediments that prevented ocean water from circulating and cooling the landscape. And there was enough precipitation to grow forests in the region that had been a “polar desert.”
Gosse and Rybczynski say it is hard to know how the Arctic will respond in coming decades to the warming linked to human production of greenhouse gases. The average global temperature is expected to warm by at least 2 C with more pronounced warming in the Arctic, which is already evident in the record summer Arctic ice retreats in recent years.