Agence France-PresseOctober 14, 2021 6:20:37 PM
A jaw bone fossil could prove that domesticated dogs have lived in Central America for 12,000 years, according to a study by Latin American scientists.
The dogs, and their masters, potentially lived alongside giant animals, the researchers say.
A 1978 excavation in Nacaome, northeast Costa Rica, found late Pleistocene bone remains.
Excavations began in the 1990s and yielded the remains of a giant horse, Equus sp, a glyptodon (a large armadillo), a mastodon (an ancestor of the modern elephant), and a jaw chunk of what was originally thought to be a coyote skull. .
“We thought it was very strange to have a coyote in the Pleistocene, that is, 12,000 years ago,” Costa Rican researcher Guillermo Vargas told AFP.
“When we started looking at the bone fragments, we started to see features that could have been from a dog.
“So we kept looking, we scanned it … and it showed that it was a dog that lived with humans 12,000 years ago in Costa Rica.”
The presence of dogs is a sign that humans also lived in a place.
“It seemed strange to us that a sample was classified as a coyote because it only arrived in Costa Rica in the 20th century.”
The first of its kind
The coyote is a relative of the domestic dog, albeit with a different jaw and more pointed teeth.
“The dog eats the leftovers of human food. Their teeth are not so decisive in their survival,” Vargas said.
“It hunts large prey with its human companions. This sample reflects that difference.”
Humans are believed to have migrated to the Americas via the Bering Strait from Siberia to Alaska during the last great ice age.
“The first domesticated dogs entered the continent about 15,000 years ago, as a result of the migration of Asians through the Bering Strait,” said Raúl Valadez, a biologist and zooarchaeologist at the National Autonomous University of Mexico.
“There have never been dogs without people,” Valadez told AFP by phone.
The presence of humans during the Pleistocene has been attested in Mexico, Chile and Patagonia, but never in Central America, until now.
“This could be the oldest dog in America,” Vargas said.
So far, the oldest attested dog remains have been found in Alaska and are 10,150 years old.
The University of Oxford has offered to perform DNA testing and carbon dating on the sample to discover more genetic information about the animal and its age.
The fossil is currently in the national museum of Costa Rica, but the sample cannot be re-identified as a dog without the validation of a specialized journal.
“This discovery of a dog would be the first evidence of humans in Costa Rica for a period much earlier” than is currently thought, Vargas said.
“It would show us that there were societies that could have dogs, that had surplus food, that they had dogs of desire and that these were not war dogs that could cause harm.”