Once upon a time (3.5 million years ago), the barren wasteland of Ellesmere Island in northernmost Canada was covered in vast forests, and animals like beavers, deer and giant camels. The National Post is reporting on a study just published in Nature Communications on the discovery of a mid-Pliocene camel.
Camels are commonly associated with the deserts of Africa (and now Australia), but they actually evolved in North America. They only made it over to Asia and Africa during the ice age, when glaciations caused sea level to drop and a “land bridge” emerged in Beringia, between Alaska and Siberia. The authors suggest that the modern camel evolved from these high Arctic camels, and the hump and wide hooves that are associated with the them were actually well suited for the long, cold winters that they would have experienced on Ellesmere Island.
The camel itself would have been massive. They had to scale up the bone of a modern camel by 30% to match up with the fossil. It really would have been an imposing creature.
Another interesting aspect of this study was that they were able to directly date the fossil beds. Though stratigraphically, the geological formation was clearly Pliocene (5.3-2.6 million years ago), having an exact age is useful for paleoclimate reconstructions. They used a technique called cosmogenic dating. Essentially, when a rock is exposed on the surface of the earth, various elements will undergo nuclear reactions when hit by cosmic rays, producing radioactive elements such as aluminium-26 and beryllium-10. Since the radioactive elements decay at a different rate, you can take the ratio of two of them to determine how long a rock has been buried, and therefore get an age (production of these elements diminishes when the rock is buried). In this case, the samples they collected in this study produced an age of about 3.7 million years (do note that this estimate has an error of about 0.7-1 million years).
Another implication of this study is what a warmer Arctic might look like. There are no trees on Ellesmere Island now, but back in the mid-Pliocene, there were vast forests. The nature of the sediments indicate that the Arctic archipelago would have been a connected land mass back then (Quaternary glaciation has carved out the rock and sediment between the islands). The mid-Pliocene warm period may be analogous to what will happen if increased greenhouse gas concentrations continue to warm the earth. The mid-Pliocene warm period was likely the result of optimal orbital conditions and higher greenhouse gas concentrations in the atmosphere, and the Arctic was disproportionately warmer than the rest of the world. The analysis of this study indicates that temperatures in northern Ellesmere Island were upwards of 18°C warmer than present. There is already evidence that the Arctic is warming up quite a bit, something I blogged about a few months ago.
Here is a video produced by the Canadian Museum of Nature, featuring lead author Natalia Rybczynski.