LEIPZIG, GERMANY—According to a report in Live Science, a fourth fossil of an individual of the extinct hominin species known as the Denisovans has been found in Siberia’s Denisova Cave. The specimen is estimated to be 50,000 to 100,000 years older than the other three known Denisovan fossils. “This would indicate that Denisovans were present in the Altai area for a very long time—at least as long as modern humans have been in Europe, if not much more,” said paleogeneticist Viviane Slon of the Max Planck Institute for Evolutionary Anthropology. The new fossil is a well-worn baby tooth probably shed by a girl between the ages of ten and 12. Slon and her team examined the tooth with 3-D X-rays, and analyzed a tiny bit of powdered tooth to look for DNA. The results suggest that there was a low level of genetic diversity among the Denisovans, which could indicate a small, isolated population lived in the cave. To read more about Denisovans, go to "Our Tangled Ancestry."