How old is...Complex Animal Life?

Answer 1

Do you mean "multi-celled"? The term "multi-celled" when applied to a plant or animal means that the organism is made up of several different cell types. The first multi-celled animals (metazoa) evolved over 600 million years ago.

Primitive metazoa can be grouped in three basic categories: sponge-like animals, cnidarians, and worms. The sponges, and cnidarians (corals and sea anemones), are the most primitive with about 11 specialized cell types. Worms and higher metazoa have approximately 55 specialized cells.
With the close of the Precambrian (545 mill. years ago), much of the Ediacara Biota (oldest animal-like multi-celled fossils) would become extinct. Many of them seem to be "failed experiments" in the evolution of life on Earth that became extinct just before the Cambrian "Explosion" of Life. Other Precambrian fossils do appear to be from the ancestors of modern animals. It is generally agreed that simple burrows and trace-fossils (such as Helminthopsis) found in upper Precambrian rocks were made by primitive worms. These worms, and some other members of the Ediacara Biota, survived the extinction event and took part in the greatest evolutionary event in Earth's history: The Cambrian "Explosion" of Life. Within 35 million years of the end of the Precambrian, representatives of essentially all modern phyla were present in the Cambrian seas.
Hope that helps.

Answer 2

The Icelandic Cyprine has a recorded age of approximately 340 years. it somewhat is assessed as a mollusk, yet is extra like an oyster. the subsequent greatest lifespan is a tie between the super tortoise and the bowhead whale, each and each of that have a recorded maximum lifespan of 260 years.