Rybczynski, a paleobiologist at the Canadian Museum of Nature, recalls thinking: “This is something kind of off the charts.”
It turns out she had uncovered the remains of the first camel ever found in the High Arctic.
The remarkable discovery, announced Tuesday, shows the humped creatures lived in forests that extended as far north as Ellesmere Island 3.5 million years ago during a global warm spell that the scientists say holds important lessons for the modern world.
“The camel is an ambassador for climate change,” says John Gosse, an earth scientist at Dalhousie University and co-author of the report on the camel published Tuesday in the journal Nature Communications.
The researchers say the find also provides evidence the camels now plodding over the sand dunes in Africa and the Middle East can trace their origins back to giant camels that evolved in Northern Canada.
“This is a completely new way of thinking about the traits that we see in camels today,” says Rybczynski.
The evidence suggests the animals were originally “northern forest specialists,” she says. And their iconic humps, which store fat, would have been very useful for surviving long, cold Arctic winters.
It also points to the remarkable “versatility and adaptability” of camels that now put their big feet and humps to use in the desert.
The Ellesmere camel is the latest addition to a menagerie of prehistoric creatures that have been uncovered on often barren landscapes in Canada’s Arctic.
The research team led by the Canadian Museum of Nature was exploring a rich fossil bed on Ellesmere, known as the Beaver Pond site, that contains the remains of a boreal forest and wetland as well as ancient black bears, beavers, horses, rabbits and “deerlets.”
At the suggestion of a geologist at the Geological Survey of Canada, Rybczynski says they headed down to check out a sediment ridge about 10 kilometres to the south.
They knew they were onto something when she uncovered bone fragments on that first visit in 2006. They returned in 2008 and 2010 collecting more than two dozen bits of bone.
It then took another three years of sleuthing by Canadian and British researchers to figure out the fragments came from a giant camel’s limb bone.
Rybczynski says one telling chunk was characteristic of a cloven-hoofed animal. But molecular tests provided the most compelling evidence.
Mike Buckley at the University of Manchester extracted and analyzed collagen from the bone fragments that had survived over the eons. He says the cold Arctic climate helped preserve the tightly linked collagen molecules, which vary from species to species.
Buckley’s “collagen fingerprinting” revealed the Ellesmere camel was “nearly identical” to another ancient camel unearthed years ago in the Yukon.
The testing also showed that both Canadian animals were from the same line of camels that hiked from North America into Asia over the Bering Land Bridge seven to eight million years ago.
Camels originated in North America about 45 million years ago and underwent most of their evolution on this continent before dying off. Over the years camel bones have been unearthed in Alaska and the Yukon, but the Ellesmere find is significant because it is 1,200 kilometres farther north making it the “first evidence of a High Arctic camel.”
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.
They say the fossils and sediments in the Arctic from the warm period known as the mid-Pliocene, when the camels lived on Ellesmere, could hold clues of what to expect.
“The mid-Pliocene is a historical analog for future warming,” says Rybczynski. “It is a potentially very important time for understanding processes in the High Arctic and getting our heads around what might be happening next and how fast it might happen.”