What was the first animal of earth?

There is no single definitive answer to the question of what was the first animal on Earth, as the fossil record is incomplete and different lines of evidence can lead to different conclusions. However, some of the earliest known animals include:

- Sponges: Sponges are simple multicellular animals that have been around for over 580 million years. They are filter feeders that use their pores to draw in water and filter out food particles.

- Cnidarians: Cnidarians, which include jellyfish, sea anemones, and corals, are another early group of animals that appeared around 550 million years ago. They are characterized by their radial symmetry and stinging cells called nematocysts.

- Flatworms: Flatworms are a group of acoelomate worms that include tapeworms, flukes, and planarians. They are believed to have evolved around 540 million years ago.

- Annelids: Annelids, which include earthworms, leeches, and tube worms, are segmented worms that have a coelom, or body cavity. They are thought to have originated around 520 million years ago.

- Arthropods: Arthropods, which include insects, spiders, and crustaceans, are a diverse group of animals that are characterized by their jointed appendages and external skeletons. They are believed to have evolved around 510 million years ago.

These are just a few examples of some of the earliest known animals on Earth. The evolutionary relationships between these groups and the order in which they appeared are still subjects of ongoing research and debate among paleontologists.