Scientists say the diet of prehistoric humans probably required more chewing teeth.

VOA: special.2011.08.10

Others are American blues. One,a kind of prehistoric love song, is in the style of the French romantic singer Maurice Chevalier.

VOA: standard.2009.11.25

Naturally it's called Four Corners. Nearby,you'll find the Painted Desert with sand of many colors, and the world's largest site of petrified prehistoric rock.

VOA: standard.2010.03.22