Julius Csotonyi
Artistic recreation of Epiatheracerium itjilik in its lake and forested habitat, Devon Island, early Miocene, 23 million years ago. The plants and animals depicted, including a rodent, a rabbit and the transitional seal Puijila darwini, are all based on fossilized remains found at the site.
Mammals arrived in North America later than previously thought, using a land bridge that connected Europe to Greenland and the North American continent.
A new species of rhinoceros has been discovered in an unexpected place: in the Canadian High Arctic, which is completely changing scientific understanding of the evolution and dispersal of these mammals.
The discovery “changes everything”, summarizes the article dedicated to the find — a fossil from around 23 million years unearthed on Devon Island in the territory of Nunavut, which is the northernmost rhinoceros ever identified.
The species was described by researchers at the Canadian Museum of Nature and was named Epiatheracerium itjilikin a reference to the Inuit term itjilik, which means “ice cream” or “frost”. The study, in October in Nature Ecology and Evolution, suggests that rhinos arrived in North America later than previously thought, using a land bridge which connected Europe to Greenland and the North American continent.
The discovery is based on a surprisingly complete fossil skeleton recovered from sediments of an ancient lake in Haughton Crater. About 75% of the skeleton has been identifieda rare level of preservation in the fossil record.
According to the researchers, this level of integrity allowed not only to recognize a new species, but also to revise the evolutionary tree of the rhino family.
Contrary to the current image associated with these animals, the Epiatheracerium itjilik there was no horn and had a relatively lighter constitution. It would have a size comparable to that of the modern Indian rhinoceros, although with different anatomical characteristics. Analysis of tooth wear indicates that the specimen studied died at young or intermediate adulthood.
The research reinforces the idea that rhinos had, in the past, a much wider distribution. Today only five species remain, confined to Africa and Asia, but the group existed for more than 40 million years and also occupied Europe and North America. More than 50 fossil species have already been identified.
To place this new species in the evolutionary history of the group, the team analyzed 57 other rhino species. The results point to migrations between Europe and North America through the so-called North Atlantic Land Bridgea route that could have remained active for land mammals until the Miocene, much later than previous hypotheses indicated.
The majority of the fossil was discovered in 1986, but now, partial proteins have been recovered from the animal’s tooth enamel that will open up new possibilities for investigating ancient biomolecules and reconstructing mammalian evolution.
Today an arid, icy landscape, Haughton Crater was millions of years ago covered in temperate forest, showing how the Arctic continues to reveal a past radically different from the present.
