When we think of hyenas, we usually picture them in the savannah or in a dry environment surrounded by lions or elephants, but this has not always been the case. Thanks to new research, we now know with certainty that ancient hyenas once lived in the Canadian Arctic regions.
The study led by the University at Buffalo reveals that two ice age fossil teeth discovered in Yukon Territory, inside the Canadian Arctic circle belonged to the so-called “running hyena” Chasmaporthetes. The discovery helps us understand how these animals reached North America from Asia.
We spoke to Jack Tseng, the first author of the study and assistant professor of pathology and anatomical sciences at the University at Buffalo.
These two fossils are not a new discovery in themselves. They were found almost four decades ago in the Yukon region among tens of thousands of fossils.
The two fossils were first identified as belonging to some kind of hyenas and were stored in the collections of the Canadian Museum of Nature in Ottawa, Ontario.
It is not until last February, when Jack Tseng came to the Canadian capital and compared the two fossils to a global sample of hyena fossils found elsewhere, that they were able to pin down exactly the identity of this particular hyena.
Understand how hyenas got to North America
Scientists long suspected that hyenas crossed from Asia to North America thanks to discoveries of fossils on both sides of the Pacific: in southern North America, on the one hand, and in Asia, Europe and Africa on the other.
This kind of migration was not unique to these mammals as many animals did the same over the years. Scientists think they did so when they discovered new environmental opportunities, new areas. In the case of these hyenas, the assumptions are that they moved when a geologic bridge formed between North America and Asia as sea levels changed, explains M. Tseng.
And this kind of migration also applied later to early humans who colonised North America by travelling on foot.
But thanks to this new discovery, scientists now have evidence of this migration, but it also helps them to better understand hyenas.
If we look at hyenas today, they are mostly found in dryer regions, close to the equator and they live in open plains.
Now, compared to what we know about the Arctic region, there was much less biodiversity and environmental conditions were much harsher there. This difference prompts scientists to rethink hyenas’ adaptability.
Hyenas existed for about 4 million years in North America
According to the different discoveries, scientists can say that hyenas arrived on the northern American continent around 5 million years ago and probably disappeared just over one million years ago.
The study reveals that the extinction of hyena in North America can be explained by different factors:
- Several potential competitors—other predators like bones cracking canidae from the dog family. These could have been ancestors of modern wolves, hunting dogs as well as gigantic short faced bears. Hyenas could have not been able to compete with them.
- Their environment was changing. Their resources dried up or the climate got much colder.
To answer that question but also understand how they adapted to their new environment, palaeontologists would need to find a bigger fossil of such hyenas. These seem to be pretty rare as no one as found one in years of expedition but Jack Tseng and other scientists are ready to continue their expeditions to find that answer.
You can listen to the full interview with Jack Tseng here: