來自 Hong Kong
Well, as I mention before. The most reasonable explanation is the calcification of organisms. Actually, there are increasingly more pre-cambrian fauna found over the world. And the Changjiang biota told us that in early age, most animals do not process a hard tissue like shells or hard skeleton (like we found some shell-less trilobite in the formation ). The soft tissues are readily to be decompose and hard to preseve so many years as fossils. However, after mid-cambrian, many animals started to develop a harden, calcified tissue. Those tissues provides amour for protection, weapons for tearing preys and most importantl to us, they are hard and not easily to be decomposed. Thats why, relatively easy for preservation of fossils provide an illusion of 'cambrian bloom' for us due to explosively more fossil to be found after mid-cambrian.
So if there is cambrian explosion, i think it is due to explosion of fossil to be found and explosion of different animals having hard tissues, not their number