Arctic giant camel discovered
Researchers find the remains of a primordial camel in the far north of CanadaRead out
Today, camels live mainly in hot and dry areas - hence their nickname "desert ships". But about 3.5 million years ago, that was different, as the discovery of camel fossils in northern Canada shows. Giant ancestors of today's camels populated then even the cold polar regions. Some typical features of today's dromedaries and bactrian camouflage might therefore have been adapted to life in the Arctic and not as previously thought in the desert, as the researchers in the journal "Nature Communications" report.
For some time, paleontologists have known that the camel family did not originate in Asia or Africa but on the North American continent - about 40 to 45 million years ago. There the primitive camels stayed there for a long time, developed further and formed new, unusual species. Only about six to seven million years ago, the camels then managed to get from the American continent via the Bering Strait to the Eurasian and finally the African continent. In parallel, some representatives of the family conquered South America.
1, 200 kilometers further north
Fossils of the early North American camels are already known. How far north the habitat of the animals extended, however, was unclear. The hitherto northernmost site is located in the Yukon Territory in northwestern Canada. However, the current find is now shifting the border by a whopping 1, 200 kilometers: it originates from Ellesmere Island, an island in northeastern Canada that is already part of the High Arctic.
There are two rich sites called Beaver Pond and Fyles Leaf Beds. In the former, scientists had earlier discovered remains of mammals, including badgers, small deer-like cloven-hoofed animals, beaver, and three-toed horses. The latter had previously revealed mainly plant remains. Now, scientists around Natalia Rybczynski of the Canadian Museum of Nature discovered in the Fyles Leaf Beds over 30 fragments of a bone that clearly came from a very large animal.
One third larger than today's camels
A closer analysis, in which the team scanned the fragments three-dimensionally and then assembled them from a computer, showed that it had to be the tibia of a large mammal. The scientists estimate the age of the find to be more than 3.4 million years - a time when camels were by far the largest mammals in North America. Therefore, it was obvious that the shin had heard a camel, says Rybczynski. The final proof for this was provided by the analysis of collagen residues that the researchers found in their bones - a stroke of luck that they presumably owe to the constant cold temperatures at the site. displayFossil fragments of a leg bone from the primordial camel, found on Ellesmere Island in the high Arctic Martin Lipman, Canadian Museum of Nature
The team made a kind of collagen fingerprint, which the researchers then compared to that of 37 other mammals, including some of the fossil camels, including the Yukon representative. The biggest coincidence was, as expected, with the Yukon camel and, more surprisingly, with the dromedaries living today. The owner of the tibia was thus definitely a camel, which belonged at least to the same lineage as the modern family members, if it did not even count to their direct ancestors, the researchers conclude.
Survive despite frost and polar night
Unfortunately, the scientists have not been able to say exactly how the animal looked. In any case, it was great the tibia is about one-third longer than the camels that live today. It probably roamed forests that resembled today's taiga and were dominated by larches. Although the temperatures were 3.5 million years higher than today there was just a warm period, the climate was not really pleasant even then: the average temperature was between minus five and plus three degrees, although it was probably still drastically lower in the winter. In addition, the camels had to cope not only with the extreme cold, but also with the polar night and thus six months of complete darkness.
Even at that time, many traits could have developed that are typical of camels today, speculate the scientists: their broad feet, for example, would have served them as well on snow-covered ground as they do today in the sandy desert. The fat storage in their horseshoes would have been almost indispensable in the long winters, and even the big eyes would have helped to penetrate the darkness. So it could well be that what is considered an ideal adaptation to the desert climate was actually developed for survival in the taiga, concludes the team. (Nature Communications, 2013; doi: 10.1038 / ncomms2516)
(Nature Communications, 06.03.2013 - ILB)