Ancient Wolf Pup Mummy Uncovered.

• Position: PERMAFROST

While water blasting at a wall of frozen mud in Yukon, Canada, a gold miner made an extraordinary discovery: a perfectly preserved wolf pup that had been locked in permafrost for 57,000 years. The remarkable condition of the pup, named Zhur by the local Tr'ondek Hwech'in people, gave researchers a wealth of insights about her age, lifestyle, and relationship to modern wolves. The findings appear in the journal Current Biology.

"She's the most complete wolf mummy that's ever been found. She's basically 100% intact--all that's missing are her eyes," says first author Julie Meachen, associate professor of anatomy at Des Moines (Iowa) University. "The fact that she's so complete allowed us to do so many lines of inquiry on her to basically reconstruct her life."

One of the most-important questions about Zhur that the researchers sought to answer was how she ended up preserved in permafrost to begin with. It takes a unique combination of circumstances to produce a permafrost mummy.

"It's rare to find these mummies in the Yukon. The animal has to die in a permafrost location, where the ground is frozen all the time, and they have to get buried very quickly, like any other fossilization process," explains Meachen. "If it lays out on the frozen tundra too long, it'll decompose or get eaten."

Another important factor is how the wolf died. Animals that die slowly or are hunted by predators are less likely to be found in pristine condition. "We think she was in her den and died instantaneously by den collapse. Our data showed that she didn't starve and was about seven weeks old when she died, so we feel a bit better knowing the poor little girl didn't suffer...