A dog skull 33,000 years old was found in the Altai Mountains of Siberia, and the discovery reveals new evidence about the relationship between man and man's best friend.
The skull was found to have a wider jaw and crowded teeth, which suggest domestication. This, along with another dog skull found in Belgium, led scientists to believe that dogs were domesticated in a variety of locations over time, rather than just once, as previously believed.
"Both the Belgian find and the Siberian find are domesticated species based on morphological characteristics," Greg Hodgins, a researcher at the University of Arizona's Accelerator Mass Spectrometry Laboratory told Fox News.
The evidence from the 33,000-year-old find has opened researchers' eyes to a new possibility: all dogs were not domesticated from the same ancestor, which means all dogs aren't necessarily related.
Hodgins explained that the proof of this was in the archaeological find.
"The argument that [the skull] is domesticated is pretty solid," said the researcher. "What's interesting is that it doesn't appear to be an ancestor of modern dogs."
The scientists used carbon dating to determine the age of the remains. Carbon-14, which is "in all living things," puts the skull at 33,000 years old, a period known as the Last Glacial Maximum.
The LGM occurred at about 26,000 and 19,000 years ago, and the extreme cold and icy conditions likely killed off the dogs found in Siberia and Belgium. Fortunately, the bones were preserved.
The longstanding relationship between human beings and dogs can now be extrapolated to have existed even before the last ice age.
"In terms of human history, before the last glacial maximum people were living with wolves or canid species in widely separated geographical areas of Euro-Asia," Hodgins explained. "[They] had been living with them long enough that they were actually changing evolutionarily."
The carbon dating also revealed that the relationship between man and dogs may have been the very first to develop among animals.
"It's really interesting that this appears to have happened first out of all human relationships with animals," said Hodgins.