This photo shows a close-up of the wolf’s head, showing its teeth. Credit: Yukon Government
As the water tossed into a frozen mud wall in the Yukon, Canada, a gold miner made an extraordinary discovery: a perfectly preserved wolf cub that had been trapped in 57,000-year-old permafrost. The remarkable condition of the chicks, called Zhùr by the local people Tr’ondëk Hwëch’in, gave researchers a wealth of information about their age, lifestyle and relationship with modern wolves. The findings appear in the journal on December 21 Current biology.
“She is the most complete wolf mummy ever found. It’s practically 100% intact – all that’s missing are her eyes, “says first author Julie Meachen, an associate professor of anatomy at Des Moines University. “And the fact that it is so complete allowed us to do so many lines of investigation on it to practically rebuild their lives.”
One of the most important questions about Zhùr that the researchers tried to answer was how it came to be kept in permafrost for a start. It takes a unique combination of circumstances to produce a permafrost mummy.
“It’s rare to find these mummies in the Yukon. The animal must die in a permafrost location, where the soil is frozen all the time and must be buried very quickly, like any other fossilization process, ”says Meachen. “If it lies on the frozen tundra for too long, it will decompose or be eaten.”
This photo shows the wolf pup as it was found. Credit: Yukon Government
Another important factor is how the wolf died. Animals that die slowly or are hunted by predators are less likely to be found in a clean state. “We think he was in the den and died instantly when the beam collapsed,” says Meachen. “Our data showed that he did not starve and was about 7 weeks old when he died, so we feel a little better knowing that the poor girl did not suffer too long.”
In addition to finding out how Zhùr died, the team also managed to analyze their diet. As it turns out, her diet was strongly influenced by how close she lived to water. “Normally, when you think of wolves in the ice age, you think of them eating bison or musk oxen or other large animals on land. One thing that surprised us was that it eats aquatic resources, especially salmon. “
Analysis of Zhùr’s genome also confirmed that she is descended from ancient wolves in Russia, Siberia and Alaska, which are the ancestors of modern wolves. Although Zhùr’s analysis has given researchers many answers about the wolves of the past, there are still some remarkable questions about Zhùr and her family.
This photo shows an X-ray view of wolf cubs. Credit: Yukon Government
“We were asked why he was the only wolf found in the lair and what happened to his mother or siblings,” says Meachen. “She may be the only baby. Or the other wolves were not in the pit during the crash. Unfortunately, we will never know. “
The specimen has a special significance for the locals Tr’ondëk Hwëch’in, who agreed to exhibit Zhùr at the Yukon Beringia Interpretation Center in Whitehorse. It is cleaned and preserved, so it will remain intact for years to come, allowing it to travel to other locations in the Yukon. And the team of researchers predicts that there could be more and more permafrost mummies found in the coming years.
“A small advantage of climate change is that we will find more of these mummies as the permafrost melts,” says Meachen. “This is a good way for science to better reconstruct that period, but it also shows us how much our planet is warming. We really have to be careful. “
Reference: “A pup mummified Pleistocene gray wolf pupp” by Julie Meachen, Matthew J. Wooller, Benjamin D. Barst, Juliette Funck, Carley Crann, Jess Heath, Molly Cassatt-Johnstone, Beth Shapiro, Elizabeth Hall, Susan Hewitson and Grant Zazula , 21 December 2020, Current biology.
DOI: 10.1016 / j.cub.2020.11.011
This work was supported by the MJ Murdock Charitable Trust awarded to Dr. Matthew Wooller at the UAF.