What is the sudden appearance of a large array of animal life known as?

The correct answer to the question: What is the sudden appearance of a large array of animal life known as, would be, in fact, the Cambrian Explosion.

Explanation:

The Cambiran explosion is defined in Paleobiology precisely as a moment during the Paleozoic Era, when suddenly there was a massive appearance of animal species, and animal life, when before there hadn´t been such an event. Although none of the species from that time survived the biggest massive extinction event in the planet´s history, it still showed a jump towards what would be modern animal life.

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link:

not sure if this is what you'r looking for eubacteria and archaebacteria