June 18 (UPI) -- Today, hyenas are found only in the warmer climates of Africa and Asia, but new research suggests the scavengers roamed the Arctic during the last ice age.
In a paper published Tuesday in the journal Open Quaternary, paleontologists described a pair of fossilized teeth belonging to Chasmaporthetes, an extinct genus of hyenas -- sometimes called the hunting or running hyena.
The teeth were first unearthed in the 1970s. Researchers guessed the teeth belonged to hyenas, but a formal analysis was never completed.
"Fossils of this genus of hyenas had been found in Africa, Europe and Asia, and also in the southern United States," Jack Tseng, paleontologist at the University of Buffalo, said in a news release. "But where and how did these animals get to North America? The teeth we studied, even though they were just two teeth, start to answer those questions."
Like early humans, ancient hyenas probably trekked across Beringia, the land bridge that connects Asia and North America when sea levels drop. From the Yukon, the hyenas migrated south into Mexico. The newly identified teeth suggest running hyenas were able to survive in the Arctic.
"It is amazing to imagine hyenas thriving in the harsh conditions above the Arctic Circle during the ice age," Grant Zazula, a paleontologist for the Yukon Government. "Chasmaporthetes probably hunted herds of ice age caribou and horses or scavenged carcasses of mammoths on the vast steppe-tundra that stretched from Siberia to Yukon Territory."
Scientists estimated the age of the teeth between 850,000 and 1.4 million years old. But hyenas moved into North America much earlier. Paleontologists have previously found 5-million-year-old hyena remains in the southern United States.
Hyenas disappeared from North America before the arrival of the first humans, some 500,000 years ago, but scientists aren't sure why. Some researchers suggest the carnivores were pushed out by another adept scavenger, the short-faced bear Arctodus simus, which lived in North America until the end of the ice age, around 12,000 years ago.