JOIN USA dog's skull, which had lain in a Siberian cave for 33,000 years, presents the oldest evidence of domestication of the canine.
The latest find comes after a dog's skull was found in Belgium and shows that man's best friends may have originated from more than one ancient ancestor, contrary to what some DNA evidence previously has indicated.
"Both the Belgian find and the Siberian find are domesticated species based on morphological characteristics," said Greg Hodgins, researcher at the University of Arizona's Accelerator Mass Spectrometry Lab and study co-author.
"Essentially, wolves have long thin snouts and their teeth are not crowded, and domestication results in this shortening of the snout and widening of the jaws and crowding of the teeth," said Hodgins, according to an Arizona statement.
The skull found in the Altai mountain is extraordinarily well preserved, said Hodgins, enabling scientists to make multiple measurements of the skull, teeth and mandibles that might not be possible on less well-preserved remains.
"The argument that it is domesticated is pretty solid," said Hodgins. "What's interesting is that it doesn't appear to be an ancestor of modern dogs," said Hodgins. Arizona's Accelerator Mass Spectrometry Lab used radiocarbon dating to determine the age of the Siberian skull.