A jaw fossil could be the key to establishing that 12,000 years ago dogs inhabited Central America, along with giant animals, according to a study by Latin American researchers. And if there was a dog, there was a master.
In 1978, a deposit with bone remains from the late Pleistocene (between 12,000 and 10,000 years BC) was found in Nacaomé, in the province of Guanacaste, in northwestern Costa Rica. Excavations in the early 1990s found the remains of a giant horse of the genus Equussp, a glyptodon (large armadillo), a mastodon and a portion of the jaw that was labeled as a coyote.
But “it seemed very strange to us that there was a coyote in the Pleistocene, that is, 12,000 years ago. When we began to see the bone remains, we began to see characteristics that could be of a dog,” explains the Costa Rican researcher Guillermo Vargas.
In search of the “Xulo”
“So we look for more, we scan it and the scanner improves what a vernier (precision measurement unit) is and gives us data that it is a dog living with people 12,000 years ago in Costa Rica,” says Vargas.
“We have researched the history of canids a lot because they are a trace of human presence (…). It seemed strange to us that this piece was classified as a coyote, because they [did not] arrive in Costa Rica until the 20th century,” he adds.
In the case of the dog, when it is domestic, “the jaw changes, the teeth have fewer cusps, they are less pointed” and they are not “for destroying bones and meat,” Vargas explains.
“The dog eats the surplus of human food. Its dentition is not so decisive to survive; the hunting of large prey is done in complicity with its human companions. This piece reflects the difference,” he adds.
Vargas, an expert in new technologies, Natalia Rodríguez, also a Costa Rican, and the Nicaraguan cultural manager Myrna Báez are part of a multidisciplinary and cross-border group that, with the support of the National Autonomous University of Mexico, has been investigating the relationship of the prehispanic cultures with these animals. Their research work is part of the “Xulo” Project, whose name refers to the dog in the original language of the Greater Nicoya archaeological zone.
And the people?
The biologist and zooarchaeologistRaúlValadezAzúa, from the Institute of Anthropological Research of the UNAM and who advises the Xulo project, observes images of the fossil and insists that it could be ‘man’s best friend’.
According to the theories of population in America, the human being migrated from Asia through the Bering Strait, a portion of sea between Siberia and Alaska, when the sea level dropped and the bottom was exposed, like a terrestrial platform, during the last great ice age.
“The first domesticated dogs entered the continent approximately 15,000 years ago, as a result of the migration of Asians through the Bering Strait. And there were never dogs without people. They moved from north to south as part of groups of hunters and gatherers”, Valadez explained.
Although there is evidence of human migration in Mexico, Chile and Patagonia, they have not been found in Central America. But the presence of dogs would confirm that there were also people with them.
“The dog-human pairing is inseparable. There are no dogs without humans (…). Sometimes it does not delve into what a finding of these can mean, but it can reconstruct the history of man,” says Valadez.
“It is almost certain that the very few dogs that managed to pass Central America and make their way into South America, where they were able to settle, had to have crossed narrow and dangerous areas,” he adds.Among these would be the hairless dogs, dating back 1,600 years, represented in archaeological pieces from Mexico and Peru.
The piece is under the protection of the National Museum of Costa Rica. “It could be the oldest dog in America,” adds Vargas. The oldest dog fossil on the continent was found in Alaska and dates to 10,150 years ago.
The researchers received an offer from the University of Oxford to do studies of mitochondrial DNA and absolute carbon-14 to the teeth of Central America. These will allow to discover more genetic information and to specify the age.To re-identify the fossil, the Museum requires that the research be validated by a specialized publication.
According to Vargas, “this discovery of the dog would be the first human evidence in Costa Rica from a much earlier period and confirms the theory of human migrations to populate the continent.”
“They show us that there were societies that could have dogs, that had a surplus of food, that had dogs for pleasure, they were not dogs for war that could do harm, as for example, the dogs that the Spaniards brought from their second trip [during colonization], which were to kill,”he considered.