A University of Maine graduate student reported finding a bone shard from a dog in a dried-out sample of human excrement that's been carbon-dated to 9,400 years ago. The bone was orange in color -- evidence that it passed through a human digestive tract.
"It just so happens this person who lived 9,400 years ago was eating dog," the graduate student, Samuel Belknap III, told The Associated Press.
In a press release from his university, Belknap described how his research took a surprising turn. "I didn't start out looking for the oldest dog in the New World," he said. "I started out trying to understand human diet in southwest Texas."
In the 1970s, fossilized human waste was found in Hinds Cave, a major archaeological site in southwest Texas near the Mexican border. Belknap and a colleague were analyzing the specimen to learn more about the diet and nutrition of people who lived in the Lower Pecos region of what's now Texas between 1,000 and 10,000 years ago. During the 2009-10 school year, they found the bone fragment and sent it off for DNA analysis at the University of Oklahoma. Tests revealed it to be the oldest-known dog fossil, from where the dog's spine connects with the skull.
"It just goes to show that sometimes, great scientific discoveries come not when we are looking for specific answers but when we are thorough ... in our examination of the evidence and open to what data it provides," the university press release quoted Belknap as saying.
Based on the size of the bone -- about 1.5 centimeters long and 1 centimeter wide -- scientists believe the ancient dog weighed 25 to 30 pounds and was similar to a species of Peruvian dogs still living today. Evidence strongly suggests that the dog was cared for by humans before being butchered, cooked and consumed in a stew, The Discovery Channel reported.
The findings are scheduled to be published in the American Journal of Physical Anthropology later this year.
Asked by the AP, Belknap admitted that he doesn't own a dog himself.