New U-Th dating tech show cave art in Spain 20ka older than first humans in Europe and must be made by Neanderthals. #NeanderthalsUseSymbols

Uranium-Thorium dating uses carbon sample of art layer to find age. Red paint and handprints show deliberate art creation at 3 cave sites.

Neanderthal artists signify long history of symbolic behavior older than 64.8kya, capable of technology once thought unique to H. sapiens.