A diverse group of organisms fossilized throughout the early part of this period is known as the "small shelly fauna." This period's disputed fossil Protomelission is sometimes claimed to be a bryozoan, which would make it the only known bryozoan from this period. This period saw the oxygenation of most seafloor sediments via organisms (10[1])burrowing through microbial mats in this period's namesake (10[1])substrate revolution. Exceptionally well-preserved fossils from this period are found in (10[1])the Burgess Shale. (10[3])A major apex predator during this (10[1])period was the anomalocaris; it may have preyed on trilobites, which appeared and rapidly diversified during this period. Almost all modern animal phyla appeared during this period. For 10 points, (10[1])animal life underwent a huge, rapid diversification (10[1])in what period's namesake explosion? ■END■