Many fossils from this period are preserved in Nevada's Bonanza King formation. The breakup of a supercontinent referred to as Pannotia or Rodinia and the Ediacaran extinction preceded this period. (15[3])Fossils of arthropods like the five-eyed Opabinia and the lobopod (15[1]-5[1])Hallucigenia from this period were discovered by Charles Walcott in the (*) Burgess Shale. (10[2])In a thesis on an (10[1])animal from this period, punctuated equilibrium was proposed by Eldredge and Gould. The appearance of trilobites determines the third stage of this period, during which the first chordates, and many other animal phyla, first originated. For 10 points, name this geologic period during which biodiversity rapidly increased in its namesake “explosion.” (10[1])■END■