The monoplacophora were well-known as a fossil group from the Cambrian to the Devonian. They were thought to be long extinct. One species was dredged up from the Pacific Ocean off Mexico in 1952. It was found to be a Monoplacophoran, and given the genus of "Neopilina". This was one of the most remarkable modern discoveries of a 'living fossil', and a Lazarus taxon.