A pair of fossilized teeth confirms the presence of hyenas north of the Arctic Circle during the last Ice Age. The discovery fills an important fossil gap that eventually explains how hyenas have landed in North America.
A pair of isolated hyenas in the Old Crow Basin in the Yukon Territory of Canada show that hyenas invaded the Arctic during the last Ice Age, a recent study in the Open Quaternary journal revealed. Paleontologist Zhijie Jack Tseng of the University of Buffalo identified the teeth preserved in the Canadian Museum of Natural History in Ottawa as belonging to the genus Chasmaporthetes which is also referred to as "running hyenas" because of its nature, generally longer legs compared to other hyenas.
The two isolated teeth were identified from over 50,000 mammalian fossils collected in the Old Crow Basin over the last 1
"The size, shape and arrangement of the cusps on both teeth is typical of hyenas in that their teeth are very sturdy and sharp-edged Tseng said in an email to Gizmodo. "We also compared tooth measurements with a global sample of fossil hyena measurements."
The teeth were originally identified as belonging to another genus of hybrids, Adcrocuta. "However, based on the geological and geographic data of the two different groups of hyenas, we came to the conclusion that these specimens are unlikely to be Adcrocuta ," Tseng said.
Why did it take so long? Tseng said the specimens were "out of sight" and they had been hiding in a museum collection for decades. Only a handful of hyena fossil experts have studied, "And once we did it, it was easy to identify and describe the specimens," he said.
Previously, paleontologists had found evidence of ancient hyenas in Africa, Eurasia, and southern North America. However, the absence of fossil evidence in the northern Arctic was like a giant puzzle with a glaring hole in the middle. The two hyena teeth are the missing part that completes the puzzle.
Importantly, the new evidence indicates that ancient hyenas crossed from Eurasia to North America by traveling over the Beringia landmass during the last Ice Age, as the sea level much lower than today. We now have "physical evidence that Chasmpaporthetes is traveling or living in the Arctic between their Asian headquarters and their newly discovered North American territory," Tseng told Gizmodo.
About 15,000 years ago humans took a similar route to North America, but the hyena migration took place much earlier. Teeth were dated by other researchers from 1.4 million to 850,000 years ago, with confidence more focused on the older figure. It is important to note that the earliest evidence of hyenas in North America dates back to a whopping 5 million years. Therefore, the first hyenas must have been crossed long before by Eurasia.
Incredibly, the new evidence also fills a huge geographic gap – a distance of more than 10,000 kilometers between the previously known new and old world records of this line, the new study.
Imagine hyenas thriving in harsh conditions over the Arctic Circle during the Ice Age, "said Grant Zazula, co-author of the study and Yukon paleontologist at a university in Buffalo. " Chasmaporthetes was probably hunting herds of glacial caribou and horses or destroying mammoth carcasses in the vast steppe tundra that stretched from Siberia to the Yukon Territory." “/>