The Piltdown Man

For over four decades the Piltdown Man was a fossil accepted by the world's scientific community as an authentic artifact of man's evolution from ape. However, the so-called Piltdown Man, originally "discovered" in 1912, was eventually revealed to be an infamous paleontological hoax.

The fossil consisted of fragments of a skull and jawbone collected from a gravel pit at Piltdown, a village near East Sussex in England. The fragments were thought by many experts of the day to be the fossilized remains of a previously unknown form of early man. The fossil, itself, was so radically different from previous and following paleological discoveries that it demanded further analysis.

The significance of the specimen remained a subject of controversy until it was finally exposed by researchers in the British Museum in November of 1953 as a forgery.

Although the upper portion of the skull was 50,000 years old (still within the threshold of a modern or later archiac homo sapien) was so roughly combined with an ape jaw that it was conspicuous and suspicious to an expert's eye. The fossil was actually a combination of the chemically treated lower jawbone and teeth of an orangutan and skull fragments from a the skull of a homo sapien. A skull that was more than likely stolen from the Museum itself.

The hoax's perpertrator, lawyer, amateur geologist and dealer of fake antiquities Charles Dawson had died in 1916. The blame, forty years later, fell on ichthyologist Arthur Smith Woodward, keeper of the Department of Geology at the British Museum, whose aid no doubt helped Dawson re-construct the fossil in the first place. By 1953, once again, the joke was on the scientific community as Smith had retired from the Museum in 1924 and died in 1944.

References:
Wikipedia, The Piltdown Man
Hoaxapedia, Piltdown Man
Oriental Rug Review, Vol. 13/2, December/January, 1993, Debunking of Three Hoaxes