If further analysis of the 40,000-30,000-year-old skeleton confirms it, it would be the first direct evidence that humans and Neanderthals interbred, they said.
Researches from the University of Ai-Marseille in France have conducted DNA and imaging studies on jawbone unearthed at a rock-shelter called Riparo di Mezzena in the Monti Lessini region of Italy, from a time when both Neanderthals and modern humans inhabited Europe.
The then compared the results with the same features from Homo sapiens.
"From the morphology of the lower jaw, the face of the Mezzena individual would have looked somehow intermediate between classic Neanderthals, who had a rather receding lower jaw (no chin), and the modern humans, who present a projecting lower jaw with a strongly developed chin," anthropologist Silvana Condemi told Discovery News.
Analysis of the ancient jaw showed individual's mitochondrial DNA is Neanderthal, and since this DNA is transmitted from a mother to her child the researchers say they believe the mother was a "female Neanderthal who mated with male Homo sapiens."
Previous research has shown the DNA of modern people with European and Asian ancestry is 1 to 4 percent Neanderthal.
Purebred Neanderthals had all died out by about 35,000-30,000 years ago, the researchers said.