10. What were the first terrestrial species on the planet?

Seaweed and other algae were the primitive foundations of underwater ecosystems. Plankton and phytoplankton (a group of plant and animal organisms, generally tiny, that float and passively move in salt or fresh water) were the key primary producers, the general foundations of the oceanic food chain. Many millions of years later, fish, after a slow evolution, evolved into amphibians, and from them emerged giant lizards, birds, and land mammals. Some later returned to the ocean as seals, dolphins, and whales.