I thought it would be a good idea to list the earliest known representatives of the four major racial types, i.e., Australoids, Caucasoids, Mongoloids, and Negroids. These dates represent the latest possible time after which the existence of these types is guaranteed; of course, by definition, they must have existed for some time before.
The first known Caucasoid is Mladec 1 from the Czech Republic, dated to 31,000BP.
The first known Australoid is Moh Khiew Cave from Thailand, dated to 25,800BP.
The first known Mongoloids appear in early Neolithic sites in China, such as Baoji and Huaxian around 7,100BP.
The earliest know Negroids date from the ~14,500-12,500BP site of Jebel Sahaba in Lower Nubia. Pictured below is Jebel Sahaba 117-10.