A fossil hominin species that lived in Europe and western Asia between about 400 000 and 40 000 years ago, when the climate was much colder than today. Neanderthals are now generally regarded as a distinct species from humans, Homo neanderthalensis. The fossil remains indicate that Neanderthals were fairly short, strongly built, and had low brows but that the brain size was the same as, or larger than, modern humans. They were nomadic cave dwellers who buried their dead. Early modern humans in Eurasia overlapped with Neanderthals from about 65 000 years ago until the Neanderthals went extinct, possibly the culmination of competition with the more advanced stone tool technology of humans. Studies have shown that present-day humans in Asia, New Guinea, and Europe each carry about 2.5% of Neanderthal DNA, and collectively may have about 20% of Neanderthal genes, a legacy of interbreeding after humans first spread from Africa. The name is derived from the site in the Neander valley, Germany, where fossils were found in 1856.

http://humanorigins.si.edu/evidence/human-fossils/species/homo-neanderthalensis Illustrated account of Neanderthal features and fossil record, from the Smithsonian Institution