Miners had found a human skull beneath…

Miners had found a human skull beneath a layer of lava, one hundred and thirty feet (forty meters) below the surface of the earth on February 25, 1866.

The skull had passed into into the hands of Josiah Whitney, the State Geologist of California as well as a Professor of Geology at Harvard University.

Found in in Calaveras County, California, it is known as the Calaveras Skull.

Coincidentally, "calaveras" is the Spanish word for "skulls".

A year before the skull came to his attention, Whitney had published his belief that humans, mastodons, and elephants had coexisted and the skull only serves as proof of his convictions.

After careful study, he officially announces its discovery at a meeting of the California Academy of Natural Sciences on July 16, 1866, declaring it evidence of the existence of Pliocene age man in North America, which would make it the oldest known record of humans on the continent.

However, its authenticity is immediately challenged, and it will later revealed to be a hoax.