Hoax in which bone fragments found in a gravel pit in East Sussex were presented as the fossilised remains of an early human (8,3)
I believe the answer is:
piltdown man
(Other definitions for piltdown man that I've seen before include "Hoax purporting to be fossil hominid" , "1912 Sussex fossil hoax - not limp wand (anag)" , "old fraud!" , "[HOAX] - with 7a" , "forgery" .)