Fossils on Ellesmere Island suggest famous desert dweller got its start in the cold
The desert’s most iconic creature may be a snow lover at heart. Scientists have unearthed fossils of a giant camel that roamed the Arctic more than 3 million years ago, when the region was warmer than today and blanketed by a boreal forest. The discovery, reported online March 5 in Nature Communications, suggests modern camels probably descended from a cold-dwelling ancestor.
“I’m not surprised you’re finding a camel up there,” says Christine Janis, a paleobiologist at Brown University in Providence, R.I., who was not involved in the discovery. Many camel characteristics, such as long legs for efficient walking and fat-storing humps, may be adaptations to living in environments like the Arctic, where food is sparse and distributed at distant intervals, she says.
A team led by paleobiologist Natalia Rybczynski of the Canadian Museum of Nature in Ottawa found roughly 30 fragments of a camel’s lower leg bone on Ellesmere Island in the Canadian Arctic. The researchers estimate the animal’s leg was 29 percent larger than a modern camel’s. Back-of-the-envelope calculations indicate the beast stood 2.7 meters at its shoulders, Rybczynski says, and weighed up to 900 kilograms.
The researchers determined that the fragments belonged to a camel by comparing collagen proteins extracted from the bones to collagen from 37 modern mammal species. The dromedary camel was the best match.
The protein was also nearly identical to collagen from more-recent camel fossils found in the Yukon Territory, which date to between 2.6 million and 10,000 years ago. In 2011, Rybczynski’s coauthor C. Richard Harington, also of the Canadian Museum of Nature, concluded in Quaternary Science Reviews that the Yukon bones resemble an extinct camel of the genus Paracamelus that lived in Eurasia as early as about 7.5 million years ago.
Scientists think Paracamelus gave rise to modern camels. Since the camel lineage originated in North America, Rybczynski says Paracamelus probably did too, crossing into Eurasia when a land bridge connected Alaska and Russia. Scientists had thought that these camels evolved from an ancestor that lived in North America’s lower latitudes. Instead, she says, Paracamelus’ connection to the Yukon and Ellesmere Island fossils suggests the camel ancestor came from the forests of the far north.