Nearly 10,000 years ago, man's best friend provided protection and companionship -- and an occasional meal.
That's what researchers are saying after finding a bone fragment from what they are calling the earliest confirmed domesticated dog in the Americas.
Samuel Belknap III, a University of Maine graduate student, found the fragment while analyzing a dried-out sample of human waste unearthed in southwest Texas in the 1970s. A carbon-dating test put the bone's age at 9,400 years, and a DNA analysis confirmed it came from a dog -- not a wolf, coyote or fox, Belknap said.
Because it was found deep inside a pile of human excrement and was the characteristic orange-brown color that bone turns when it has passed through the digestive tract, the fragment provides the earliest direct evidence that dogs -- besides being used for company, security and hunting -- were eaten by humans and may even have been bred as a food source, he said.
Belknap wasn't researching dogs when he found the bone. Rather, he was looking into the diet and nutrition of the people who lived in the Lower Pecos region of Texas between 1,000 and 10,000 years ago.
"It just so happens this person who lived 9,400 years ago was eating dog," Belknap said.
Belknap and other researchers from the University of Maine and the University of Oklahoma's molecular anthropology laboratories, where the DNA analysis was done, have written a paper on the findings, which is awaiting publication.
The earliest dogs in North America are believed to have come with the early settlers across the Bering land bridge from Asia to the Americas 10,000 years ago or earlier.
Archaeological records of dogs go back 31,000 years from a site in Belgium, 26,000 years in the Czech Republic and 15,000 years in Siberia, said Robert Wayne, a professor of evolutionary biology at the University of California at Los Angeles and a dog evolution expert. But canine records in the New World are not as detailed.