LONDON — It was an archaeological hoax that fooled scientists for decades. A century on, researchers are determined to find out who was responsible for Piltdown Man, the missing link that never was.

In December 1912, it was announced that a lawyer and amateur archaeologist named Charles Dawson had made an astonishing discovery in a gravel pit in southern England — prehistoric remains, up to 1 million years old, that combined the skull of a human and the jaw of an ape....

It was 40 years before the find was definitively exposed as a hoax, and speculation about who did it rages to this day. Now scientists at London’s Natural History Museum — whose predecessors trumpeted the Piltdown find and may be suspects in the fraud— are marking the 100th anniversary with a new push to settle the argument for good....