National Geographic

The Giant Camels of the Prehistoric High Arctic

Fossils can be astonishingly beautiful testaments of evolution and prehistoric time. There are few things I like better than wandering a museum’s fossil hall, admiring the skeletal architecture of a sauropod’s neck or the polished curl of an ammonite’s shell. But many, many fossils are ugly, hopelessly broken pieces of organisms past. The showroom pieces in museum halls only represent the rare, visually-magnificent few; or at least animals that paleontologists can reconstruct to the point where the remains take on an appealing cast of near-vitality. Nevertheless, even fossil crumbs have stories to tell if we know how to draw them out. One such skeletal remnant has just revealed the presence of an enormous camel that wandered forests of Canada’s High Arctic when the world was warmer.

The shards of the Ellesmere camel tibia. Photo © Martin Lipman, via the Canadian Museum of Nature.

The shards of the Ellesmere camel tibia. Photo © Martin Lipman, via the Canadian Museum of Nature.

The fossil is the focus of a new Nature Communications paper by paleontologist Natalia Rybczynski and colleagues. From a purely aesthetic standpoint, the bone looks terrible. The thirty tan shards don’t even make up a full element. Altogether, laced together digitally, the scraps constitute part of a tibia from some sort of hoofed mammal. If they had been found in another deposit, the cracked fossils may not have even merited collecting, but these were the first bones found among the ancient plants of the Fyles Leaf Bed, and were apparently all that was left of a huge and hitherto undiscovered herbivore.

But what kind of beast was it? In the paper, Rybczynski and coauthors point out that the anatomical landmarks on the pieces only narrow the fossil down to the level of artiodactyl – hoofed mammals with an even number of toes such as deer, cows, and camels. The size of the bone suggested that the tibia fragment came from a camel. At the time the bone was buried, about 3.4 million years ago, the largest artiodactyls in North America were camels. By using the proportions of dromedary and Bactrian camels as a proxy, the researchers estimated that the complete tibia would have been about 22 inches long, or about 29% longer than the same bone in the extant animals. Of course, that assumed that the bone truly did belong to a camel.

Morphology alone did not solve the mystery. The solution was contained within the bone itself. Collagen is a major component of bone – it’s the primary protein that makes up the flexible part of skeletal elements. Not only is collagen able to survive for a long time in the fossil record, aided in this case by the cold and dry conditions that have since developed in the Arctic, but protein profiles of the material can help distinguish mammals at the genus level. With this in mind, Rybczynski and coauthors sampled prehistoric collagen from the Ellesmere camel and compared the signature of the protein with collagen from 37 other mammal species. The collagen from the High Arctic fossils most closely resembled the profiles of dromedary camels and prehistoric camel bones found in the Yukon, thought to be members of the genus that spawned modern camel species, Paracamelus. And the Ellesmere fossil was also a record-breaker – the bone belonged to a camel that lived about 750 miles further north than any other camel found on the continent.

The environment the humped herbivore foraged over was quite a bit different than those of Ellesmere Island today. Around 3.4 million years ago, the global climate was about 35 degrees Fahrenheit warmer than at present, and the High Arctic habitats of Pliocene Ellesmere Island might have been as much as 70 degrees Fahrenheit hotter. The high latitude habitat still experienced chilly winters and almost six months of darkness, but the cold was not so harsh in the Pliocene. And, based on the plant fossils found at the same site, the ancient camels appear to have lived in boreal forests that were on the edge of the tundra.

The existence of a huge camel in northern Canada might seem strange, but, in fact, the real oddity is that there are no longer any native camels in North America. The first camelids evolved in North America about 45 million years ago, and the herbivores proliferated into a variety of forms and sizes. By about 12,000 years ago, though, the last of North America’s camels were wiped out in the continent’s megafaunal extinction, leaving only two lineages present elsewhere in the world – the dromedary and Bactrian camels of Africa and Asia, and the llamas, alpacas, guanacos, and vicuñas of South America. In the big picture of camel evolution, the Ellesmere animal was on the dromedary and Bactrian branch and relatively close to the origin of those still-living species.

Rybczynski and coauthors refrain from identifying the Ellesmere camel down to genus or species. Based on the collagen evidence, the herbivore might have been a northern population of Paracamelus related to the population preserved in the younger Yukon deposits, but additional bones from both sites are needed to be sure. Still, the paltry remains of the Yukon and Ellesmere camels indicate that the hebivores were capable of surviving in northern forests, and hint that camels as we know them today carry traits that evolved to help them survive in such cold habitats. The low-crowned teeth of modern camels might be an inheritance of ancestors that browsed in northern forests, Rybczynski and coauthors suggest, and a fatty hump that lets camels withstand harsh desert environments would have been just as advantageous in high latitude Pliocene habitats where the sky was dark for half the year. Adaptations that allow camels to thrive in deserts might have evolved in cool forests first, a testament to the flexibility of the wandering artiodactyls despite their ultimate extinction on the continent of their birth.

Reference:

Rybczynski, N., Gosse, J., Harington, C., Wogelius, R., Hidy, A., Buckley, M. 2013. Mid-Pliocene warm-period deposits in the High Arctic yield insights into camel evolution. Nature Communications. 4, 1550: 1-9 DOI: 10.1038/ncomms2516

There are 9 Comments. Add Yours.

  1. Paul Braterman
    March 5, 2013

    “the real oddity is that there are no longer any native camels in North America”; isn’t there a similar anomaly for equids? And do we have an explanation?

  2. suibne
    March 6, 2013

    global warming hold outs.

  3. https://greenerlivingstore.com
    March 6, 2013

    Camels are surprisingly versatile creatures. Many years ago, they were used up in Northern Canada for transporting goods. In my mind, that means that the climate was not necessarily warmer back then for the camels to have lived there.

    [The estimated warmer climate of 3.4 million years ago is based on geological data, as well as the fact that there was a forest where there is now much colder tundra. - BS]

  4. Thomas Bank
    March 7, 2013

    Camels have also been used to transport goods in the blizzard conditions that exist in the Steppes of Central Asia and on the old Silk Road from China to Russia.

  5. Robert Tippett
    March 8, 2013

    This is an extrordinary discovery the Paracamelus was never found in the Northern American territories of the other Ellesmere creatures. This is a very interesting topic and I need to find more topics pertaining to this situation

  6. Daniel
    March 8, 2013

    Paul asked “the real oddity is that there are no longer any native camels in North America”; isn’t there a similar anomaly for equids? And do we have an explanation?

    Yes, the explanation is that the Indians wiped out most large species by hunting when they entered the Americas at the end of the last Ice Age.

  7. Kurt Kohler
    March 8, 2013

    “Around 3.4 million years ago, the global climate was about 35 degrees Fahrenheit warmer than at present, and … Pliocene Ellesmere Island might have been as much as 70 degrees Fahrenheit hotter.”

    These temperatures can’t be right! Global temperatures in the mid-Pliocene were around 2-3 degrees C hotter then present. Is there a missing decimal point?

  8. John Monger
    March 8, 2013

    It makes sense that they went extinct 12,000 years ago since other megafauna species went extinct between 13,000 and 9,000 years ago like the mastodon due to climate change and humans.

  9. Tim Morris
    March 10, 2013

    I agree, camels are not always hot weather animals. They are animals of extremes. Wild bactrian camels live in the highlands of mongolia, where it is dry, yet very cold. The only drinking water is snow. In some parts of Russia, camels are used as pack animals throughout the year. The main thing that restricts modern camels is humidity, if it is too humid, they get sinus infections and colds, this has happened in central Europe. I do not know if dromedaries have the same problem…However, there were small prehistoric camels in panama and Florida, so surely the ancient varieties may have evolved humidity tolerance.

Add Your Comments

All fields required.

Related Posts