In an ancient grave in what鈥檚 now northwestern Argentina, a person was buried with a canine companion 鈥� but this animal friend wasn鈥檛 a dog, according to new research. The burial held the skeleton of a type of canid that may have once competed with dogs for human affection: a fox.
Humans and dogs have a long history. The relationship between the two species is tens of thousands of years old. However, a fresh analysis of evidence from a Patagonian burial dating back about 1,500 years hints at a similar close connection between a hunter-gatherer in southern South America and the large extinct fox species Dusicyon avus.
Archaeologists originally uncovered the near-complete D. avus skeleton buried alongside a human at Cañada Seca, a site in northern Patagonia, in 1991. There were no cut marks on the bones, so the fox hadn鈥檛 been eaten, said , a researcher with the Wellcome Trust Palaeogenomics and Bio-Archaeology Research Network at the University of Oxford鈥檚 School of Archaeology in the United Kingdom.
An in-depth analysis of ancient DNA and radiocarbon dating confirmed the fox鈥檚 species and age, and examination of collagen in the fox鈥檚 remains revealed that it ate the same food that this group of humans did. Along with the skeleton鈥檚 placement in the grave, the animal鈥檚 diet suggested that the fox was tame and may have been kept as a pet, scientists reported Wednesday in the journal .
The discovery adds to a growing body of evidence from burial sites on other continents indicating that individual foxes were tamed by humans and shared a connection based on companionship.
The fox and hunter-gatherer society
D. avus lived from the Pleistocene Epoch (around 2.6 million to 11,700 years ago) into the Holocene, becoming extinct about 500 years ago. It was roughly the size of a modern German shepherd but far less bulky, weighing up to 33 pounds (15 kilograms).
鈥淚n general, Dusicyon avus has a carnivorous kind of diet,鈥� said Lebrasseur, who co-led the study with , a researcher with Argentina鈥檚 National Scientific and Technical Research Council. But when the scientists tested the fox skeleton from the burial, they found that its diet was less carnivorous than expected, and more similar to the diets of humans.
鈥淭hat suggests either the community was feeding it, or it was around the community and feeding on the kitchen refuse,鈥� Lebrasseur told CNN. 鈥淚t would suggest that there鈥檚 a closer relationship and integration of the canid within the society.鈥�
The notion of foxes as pets in South America aligns with evidence from other fox burials in Europe and Asia, said , a paleobiologist at the Universidade da Coruña in Spain. Grandal-d鈥橝nglade, who was not involved in the new study, previously Bronze Age graves in the Iberian Peninsula that included dozens of dogs and four foxes buried alongside people. Researchers found that the foxes had been arranged much like the dogs were, suggesting that they, too, were companions for humans.
鈥淭here is no reason why foxes could not be domesticated,鈥� Grandal-d鈥橝nglade told CNN in an email. 鈥淲e know that humans in many completely different societies often keep domestic animals (not only canids, but e.g. monkeys, birds, reptiles) simply as companion animals. When viewed in this light, more and more sites appear where foxes seem to have played the role of pet animals.鈥�
Finding D. avus in a human grave was surprising for another reason 鈥� while the species was once widespread across southern South America, it was previously unknown in this part of Patagonia. Hunter-gatherers who lived in the region typically stayed within a range of about 44 miles (70 kilometres), so they likely encountered the friendly fox within that range, according to the study.
鈥淭he Dusicyon avus must have been part of the nearby vicinity, to be able to be integrated within the community,鈥� Lebrasseur said.
What fox burials reveal about 'man's best friend'
The analysis also shed light on what drove the foxes to extinction 鈥� or rather, what didn鈥檛. One hypothesis suggested that the foxes interbred with dogs that European colonizers introduced to South America, and that interbreeding eventually caused the foxes鈥� lineage to peter out. But the fox's DNA told a different story, the study authors reported.
鈥淏ased on what we were able to recover and the technique that we developed at Oxford a few years ago, we were able to suggest that the hybridization between domestic dogs and Dusicyon avus would not have been able to produce fertile offspring,鈥� Lebrasseur said.
However, it鈥檚 still possible that dogs weren鈥檛 entirely innocent in the foxes鈥� decline. With a similar diet to D. avus, dogs may have helped speed the foxes鈥� extinction by outcompeting them. Dogs could also have carried and transmitted diseases that sickened the foxes, Lebrasseur added.
Experts often explain dog domestication as something that happened because humans realized that they could put dogs to work as hunters or herders, Grandal-d鈥橝nglade said. But the D. avus skeleton at Cañada Seca and other fox burials hint that an animal didn鈥檛 need to be a useful worker to be nurtured by humans 鈥� it could simply be a friend.
鈥淭he proliferation of canids of different species in close relationship with humans seems to indicate that in principle it was a relationship of affection, of companionship,鈥� Grandal-d鈥橝nglade said. 鈥淭he fact that we find them in so many different societies and on different continents indicates that keeping animals for companionship, and not only as working or meat animals, is an ancestral trait in humans.鈥�
Mindy Weisberger is a science writer and media producer whose work has appeared in Live Science, Scientific American and How It Works magazine.
