Giant spider discovered in mine

A new species of large cave-dwelling spider, the Sierra Cacachilas wandering spider (Califorctenus cacachilensis), seen here in an abandoned silver mine in the Sierra Cacachilas mountain range near La Paz in Baja California Sur, Mexico. Photo: TNS

In the hills of Baja California, Michael Wall and Jim Berrian found a creature that’s the stuff of nightmares for most people: a cave spider nearly the size of a tarantula.

For the two San Diego Natural History Museum researchers, it was an exciting windfall – an unknown arachnid as wide across as a softball.