The Cambrian is an ancient period in geological time that lasted from 542 million years ago (mya) to 490 mya. It is the earliest time in geological history that plant and animal fossils appear in abundance. During the Cambrian a menagerie of multicell­ular life “exploded”,. . . . Creationists love the Cambrian “explosion”. To them, it proves that all the major types of animals (phyla) suddenly materialized, being instantly created by God.