14,000-year-old mummified ‘puppies’ weren’t dogs at all, new research shows

Two well-preserved ice age “puppies” found in Northern Siberia may not be dogs at all, according to new research. Still covered in fur and naturally preserved in ice for thousands of years, the “Tumat Puppies,” as they are known, contain hints of a last meal in their stomachs, including meat from a woolly rhinoceros and feathers from a small bird called a wagtail. Previously thought to be early domesticated dogs or tamed wolves living near humans, the animals’ remains were found near woolly mammoth bones that had been burned and cut by humans, suggesting the canids lived near a site where humans butchered mammoths. By analyzing genetic data from the gut contents and chemical signatures in the bones, teeth and soft tissue, researchers now think the animals were 2-month-old wolf pups that show no evidence of interacting with people, according to findings published Thursday in the journal Quaternary Research. Neither of the mummified wolf cubs, believed to be sisters, show signs of having been attacked or injured, indicating that they died suddenly when their underground den collapsed and trapped them inside more than 14,000 years ago. The den collapse may have been triggered by a landslide, according to the study. The wealth of data from the remains is shedding light on the everyday life of ice age animals, including how they ate, which is similar to the habits of modern wolves. “It was incredible to find two sisters from this era so well preserved, but even more incredible that we can now tell so much of their story, down to the last meal that they ate,” wrote lead study author Anne Kathrine Wiborg Runge, formerly a doctoral student at the University of York and the University of Copenhagen, in a statement. “Whilst many will be disappointed that these animals are almost certainly wolves and not early domesticated dogs, they have helped us get closer to understanding the environment at the time, how these animals lived, and how remarkably similar wolves from more than 14,000 years ago are to modern day wolves.” The multitude of research on these pups and other specimens also illustrates how difficult it is to prove when dogs, widely regarded as the first domesticated animal, became a part of human society. Uncovering the cubs’ eating habits Trapped in thawing permafrost, the Tumat Puppies were discovered separately at the Syalakh site, about 25 miles (40 kilometers) from the nearest village of Tumat — one in 2011 and the other in 2015. They are approximately 14,046 to 14,965 years old. Hair, skin, claws and entire stomach contents can survive eons under the right conditions, said study coauthor Dr. Nathan Wales, senior lecturer in archaeology at the University of York in England. “The most surprising thing to me is that the archaeologists managed to discover the second Tumat Puppy several years after the first was found,” Runge told CNN. “It is very rare to find two specimens that are so well preserved and then they turn out to be siblings/littermates. It’s extraordinary.” Like modern wolves, the pups ate both meat and plants. Though a woolly rhinoceros would be rather large prey for wolves to hunt, the piece of woolly rhino skin in one pup’s stomach is proof of the canids’ diet. The rhino skin, bearing blond fur, was only partially digested, suggesting the pups were resting in their den and died shortly after their last meal, Runge said. The color of the woolly rhino fur is consistent with that of a calf, based on previous research of a juvenile woolly rhino specimen found in the permafrost. Adult woolly rhinos likely had darker fur. The pack of adult wolves hunted the calf and brought it back to the den to feed the pups, according to the study authors. “The hunting of an animal as large as a wooly rhinoceros, even a baby one, suggests that these wolves are perhaps bigger than the wolves we see today,” Wales wrote in a statement. The researchers also analyzed tiny plant remains fossilizing in the cubs’ stomachs, revealing that the wolves lived in a dry, somewhat mild environment that could support diverse vegetation including prairie grasses, willows and shrub leaves. In addition to eating solid food, the pups were likely still nursing milk from their mother, according to the researchers. What scientists didn’t find was evidence that mammoths were part of the cubs’ diet, meaning it was unlikely that humans at the site were feeding the canids. Is it possible, though, that people shared woolly rhino meat with the cubs? That’s something Wales considered, but now he believes the evidence points in the other direction. “We know that modern wolves will hunt large prey like elk, moose and musk ox, and anyone who watches animal documentaries will know wolves tend to single out juvenile or weaker individuals when they hunt,” Wales wrote in an email. “I lean toward the interpretation that the Tumat Puppies were fed part of a juvenile wooly rhino (by adult wolves).” The origin of the woolly rhino meat is impossible to pinpoint — the wolf pack could have hunted the calf or scavenged it from a carcass or even a butchering site — but given the age of the cubs and the fact that the den collapsed on them, it seems less likely that humans fed them directly, Runge said. That the cubs were being reared in a den and fed by their pack, similarly to how wolves breed and raise their young today, further suggests that the Tumat Puppies were wolves rather than dogs, Wales said. Dogs vs. wolves Painting a broader picture of ice age wolves is difficult because no written sources or cave art depicting them have been found, so it is unclear how wolf packs and ancient humans would have interacted, Runge said. “We have to try to account for our own biases and preconceived notions based on human-wolf interactions today,” she wrote. “And then we have to be okay with knowing we’ll never be able to answer some of the questions.” Researchers are still trying to understand how domesticated dogs became companions to humans. One hypothesis is that wolves lived near humans and scavenged their food. But the domestication process would take generations and require humans to tolerate this behavior. Another hypothesis is that humans actively captured and hand-raised wolves, causing some of them to become isolated from wild populations, resulting in early dogs. Previous DNA tests on the cubs suggested they could have come from a now extinct population of wolves that eventually died out — and a population that did not act as a genetic bridge to modern dogs. “When we’re talking about the origins of dogs, we’re talking about the very first domesticated animal,” Wales said. “And for that reason, scientists have to have really solid evidence to make claims of early dogs.” All the evidence the authors of the new study found was compatible with the wolves living on their own, Wales said. “Today, litters are often larger than two, and it is possible that the Tumat Puppies had siblings that escaped (the same) fate,” he said. “There may also be more cubs hidden in the permafrost or lost to erosion.” Pinpointing where and when dogs were domesticated is still something of a holy grail in archaeology, evolutionary biology and ancient DNA research, said Dr. Linus Girdland-Flink, a lecturer in biomolecular archaeology at the University of Aberdeen in Scotland. Though Girdland-Flink’s research is on ancient wolves and dogs, he was not involved in the new study. But determining whether ancient remains like the Tumat Puppies are early domestic dogs, wild wolves, scavengers or tamed individuals isn’t straightforward because of the fragmented archaeological record, he said. No one piece of evidence can lead to a definitive answer. And it’s even harder to do a comparison involving cubs because adult traits help distinguish between wild wolves and domesticated dogs. “Instead, we have to bring together different lines of proxy evidence — archaeological, morphological, genetic, ecological — and think about how they all fit,” Girdland-Flink wrote in an email. “So, I really welcome this new multi-disciplinary reanalysis of the Tumat puppies.” Girdland-Flink wasn’t surprised the cubs weren’t associated with the mammoth butchering site — an absence of evidence that matters. And combined with the lack of strong genetic ties to domestic dogs, he agreed the cubs must have come from a wolf population that did not live with humans.