Classification
Here is the classification that most scientists use.
Kingdom Animalia (animals)
Parazoa (sponges)
Phylum Placozoa (small, flat sponges)
Phylum Porifera (common sponges)
Eumetazoa (more complex organisms with tissues)
Radiata (radial symmetrical eumetazoans)
Phylum Cnidaria (jellyfish, corals, and hydra)
Phylum Ctenophora (comb jellies)
Bilateria (bilateral symmetrical eumetazoans)
Mesozoa (worm-like marine parasites)
Phylum Dicyemida (round-worm like marine parasites)
Phylum Orthonectida (flat-worm like marine parasites)
Deuterostomia (vertebrates, acorn worms, sea stars, sea urchins, and more)
Phylum Chaetognatha (arrow worms)
Phylum Chordata (lancelets, tunicates, vertebrates including HUMANS)
Phylum Echinodermata (sea stars, sea urchins, sea lilies, and more)
Phylum Hemichordata (acorn worms and more)
Phylum Xenoturbella (marine worms)
Protostomia (insects, spiders, crabs, octopi, clams, snails, worms, and more)
Ecdysozoa (roundworms, shrimp, insects, spiders, crabs, and more)
Phylum Arthropoda (shrimp, insects, spiders, crabs, and more)
Phylum Kinorhyncha (mud dragons)
Phylum Loricifera (small marine animals)
Phylum Nematoda (roundworms)
Phylum Nematomorpha (horsehair worms)
Phylum Onychophora (velvet worms)
Phylum Priapulida (penis worms)
Phylum Tardigrada (moss piglets)
Lophotrochozoa (octopi, clams, snails, segmented worms, and more)
Phylum Annelida (segmented worms)
Phylum Brachiopoda (lamp shells)
Phylum Bryozoa (moss animals)
Phylum Entoprocta (goblet worms)
Phylum Mollusca (octopi, squid, clams, snails, slugs, and more)
Phylum Nemertea (ribbon worms)
Phylum Phoronida (horseshoe worms)
Phylum Sipuncula (peanut worms)
Platyzoa (flatworms, wheel animals, thorny-headed worms, and more)
Phylum Acanthocephala (thorny-headed worms)
Phylum Cycliophora (strange marine microscopic animals)
Phylum Gastrotricha (hairybacks)
Phylum Gnathostomulida (jaw worms)
Phylum Platyhelminthes (flatworms)
Phylum Rotifera (wheel animals)
Kingdom Animalia (animals)
Parazoa (sponges)
Phylum Placozoa (small, flat sponges)
Phylum Porifera (common sponges)
Eumetazoa (more complex organisms with tissues)
Radiata (radial symmetrical eumetazoans)
Phylum Cnidaria (jellyfish, corals, and hydra)
Phylum Ctenophora (comb jellies)
Bilateria (bilateral symmetrical eumetazoans)
Mesozoa (worm-like marine parasites)
Phylum Dicyemida (round-worm like marine parasites)
Phylum Orthonectida (flat-worm like marine parasites)
Deuterostomia (vertebrates, acorn worms, sea stars, sea urchins, and more)
Phylum Chaetognatha (arrow worms)
Phylum Chordata (lancelets, tunicates, vertebrates including HUMANS)
Phylum Echinodermata (sea stars, sea urchins, sea lilies, and more)
Phylum Hemichordata (acorn worms and more)
Phylum Xenoturbella (marine worms)
Protostomia (insects, spiders, crabs, octopi, clams, snails, worms, and more)
Ecdysozoa (roundworms, shrimp, insects, spiders, crabs, and more)
Phylum Arthropoda (shrimp, insects, spiders, crabs, and more)
Phylum Kinorhyncha (mud dragons)
Phylum Loricifera (small marine animals)
Phylum Nematoda (roundworms)
Phylum Nematomorpha (horsehair worms)
Phylum Onychophora (velvet worms)
Phylum Priapulida (penis worms)
Phylum Tardigrada (moss piglets)
Lophotrochozoa (octopi, clams, snails, segmented worms, and more)
Phylum Annelida (segmented worms)
Phylum Brachiopoda (lamp shells)
Phylum Bryozoa (moss animals)
Phylum Entoprocta (goblet worms)
Phylum Mollusca (octopi, squid, clams, snails, slugs, and more)
Phylum Nemertea (ribbon worms)
Phylum Phoronida (horseshoe worms)
Phylum Sipuncula (peanut worms)
Platyzoa (flatworms, wheel animals, thorny-headed worms, and more)
Phylum Acanthocephala (thorny-headed worms)
Phylum Cycliophora (strange marine microscopic animals)
Phylum Gastrotricha (hairybacks)
Phylum Gnathostomulida (jaw worms)
Phylum Platyhelminthes (flatworms)
Phylum Rotifera (wheel animals)