Answer: it produced oxygen as a waste product
Explanation: there was more free oxygen
Sponges have specialized cells and an endoskeleton, but they lack tissues and body symmetry. ... They include jellyfish and corals, both of which have radial symmetry. All cnidarians have nematocysts, and many are bioluminescent. They may exist in medusa and/or polyp form.
A niche is an organism's role in a community.
What it eats, Where it eats, When it eats, and its job in that environment.