Exposure of the Piltdown fraud. Weiner, Oakley and Le Gros Clark found ample evidence of forgery in the Piltdown remains, including the use of artificial abrasion and staining; they also applied fluorine and nitrogen analysis to determine the relative ages of the Piltdown fragments, finding that “whereas the Piltdown cranium may well be Upper Pleistocene . . . the mandible, canine tooth and isolated molar are quite modern” (p. 143).