Camels are well known for their ability to survive the hot and dry conditions of the desert, but a study suggests they once thrived in colder climes.
Scientists have unearthed the fossilised remains of a giant species of camel in Canada's High Arctic.
An analysis of protein found in the bones has revealed that this creature, which lived about 3.5 million years ago, is an ancestor of today's species.
The research is published in the journal Nature Communications
Dr Mike Buckley, an author of the paper from the University of Manchester, said: "What's interesting about this story is the location: this is the northernmost evidence of camels."
The mid-Pliocene Epoch was a warm period of the Earth's history - but surviving in the Arctic would have still been tough.
The ancient camels would have had to cope with long and harsh winters, with temperatures plunging well below freezing. There would have been snow storms and months of perpetual darkness.
Nonetheless, at this time, the polar region would have been covered in forest.
Over the course of three expeditions, which began in 2006, researchers from the Canadian Museum of Nature collected 30 fragments of fossilised leg bone from Ellesmere Island in Canada.
Their size suggested that the animal was about 30% larger that today's camels, measuring about 2.7m from foot to shoulder.
Despite its bulk, the researchers believe it would have been similar in appearance - although it probably had a shaggier coat to stay warm.more