In 1922, a Nebraska geologist sent a fossilized tooth to Henry Osborn, head of the American Museum of Natural History. Osborn was involved with the Scopes Monkey Trial, and was delighted at the new evidence for his side. He rushed to publication, and announced the new species Hesperopithecus ("Ape of the western world"). It seemed, he said, more human than ape.
But what happened next? The answer is that Osborn himself went to Nebraska in the summers of 1925 and 1926. Many more teeth were found, and it became apparent that they weren't from an ape. They belonged to an extinct peccary, Prosthennops. A retraction of Hesperopithecus was published in 1927.
Now, was there a fraud? No. Osborn made every effort to obtain more evidence, and when he found it, he published that too, even though he was embarrassed and disappointed.
Did the scientific community swallow this whole? Well, yes and no. Some colleagues stated that Osborn was wrong. One foolishly had a drawing made of Nebraska Man, but Osborn himself referred to that drawing as "a figment of the imagination of no scientific value".
Some Creationists have claimed that Nebraska Man was part of the evidence at the Scopes Monkey Trial. In fact, Judge Raulston excluded all expert testimony, except that of William Jennings Bryan.
For more detail, see:
Chapter 29, An Essay on a Pig Roast, Bully for Brontosaurus, Reflections in Natural History, Stephen Jay Gould, W.W. Norton 1991A search at the Talk.Origins FAQ site will turn up about 20 documents.