The following is a list of the classes in each phylum of the kingdom Animalia. There are 105 classes of animals in 24 phyla in this list (the phyla Entoprocta, Gastrotricha, Gnathostomulida, Loricifera, Micrognathozoa, Onychophora, Orthonectida and Phoronida contain no classes, nor does the subphylum Xenoturbellida). However, different sources give different numbers of classes and phyla. For example, Protura, Diplura, and Collembola are often considered to be the three orders in the class Entognatha. This list should by no means be considered complete and authoritative and should be used carefully.
Annelida (segmented worms)
Polychaeta (bristle worms, paraphyletic with respect to Clitellata and Sipuncula) Clitellata (earthworms, leeches) Sipuncula (peanut worms)
Arthropoda (insects, crustaceans, arachnids, centipedes and others)
Chelicerata Source: Arachnida (spiders, scorpions, and kin) Merostomata (horseshoe crabs) Pycnogonida (sea spiders)
Myriapoda Source: Chilopoda (centipedes) Diplopoda (millipedes) Pauropoda Symphyla (pseudocentipedes)
Pancrustacea Source: Ostracoda (seed shrimp) Mystacocarida Ichthyostraca (tongue worms and fish lice) Copepoda Malacostraca (crabs, lobsters, crayfish, krill, various shrimp, woodlice, and kin) Tantulocarida Thecostraca (barnacles) Cephalocarida (horseshoe shrimp) Branchiopoda (fairy shrimp, tadpole shrimp, water fleas, and clam shrimp) Remipedia
Hexapoda Source: Entognatha (coneheads, two-pronged bristletails and springtails. paraphyletic with respect to insects) Insecta (insects)
Brachiopoda (lamp shells) Lingulata Craniata Rhynchonellata
Bryozoa (moss animals) Gymnolaemata Phylactolaemata Stenolaemata
Chaetognatha (arrow worms) Sagittoidea
Chordata (vertebrates, tunicates, and lancelets)
Cephalochordata Leptocardii (lancelet)
Tunicata Appendicularia (larvaceans) Ascidiacea (sea squirts, paraphyletic with respect to Thaliacea) Thaliacea (salps, pyrosomes, and doliolids)
Vertebrata
Cyclostomata (jawless fish) Myxini (hagfish) Petromyzontida (lamprey)
Gnathostomata (jawed vertebrates)
Chondrichthyes (cartilaginous fish: chimeras, sharks and rays)
Osteichthyes Actinopterygii (ray-finned fish, which includes most familiar bony fish) Sarcopterygii Actinistia (coelacanths) Dipnoi (lungfish) Tetrapoda Amphibia (amphibians) Amniota Mammalia (mammals) Aves (birds) Reptilia (reptiles, paraphyletic with respect to Aves)
Cnidaria (marine stinging animals) Anthozoa (corals and sea anemones) Octocorallia Hexacorallia Medusozoa (jellyfish and hydrozoans) Cubozoa (box jellyfish) Hydrozoa (hydroids) Scyphozoa (true jellyfish) Staurozoa (stalked jellyfish) Endocnidozoa (marine parasites) Myxozoa Polypodiozoa
Ctenophora (comb jellies) Tentaculata Nuda (beroids)
Cycliophora (tiny marine animals) Eucycliophora
Dicyemida (rhombozoa) Rhombozoa
Echinodermata (sea stars, sea urchins, sand dollars, sea lilies, and others)
Crinozoa Crinoidea (sea lilies and feather stars)
Asterozoa Asteroidea (sea star) Ophiuroidea (brittle stars)
Echinozoa Echinoidea (sea urchins) Holothuroidea (sea cucumbers)
Hemichordata Enteropneusta (acorn worms) Pterobranchia Planctosphaeroidea
Kinorhyncha (mud dragons) Allomalorhagida Cyclorhagida
Mollusca (mollusks) Solenogastres Caudofoveata Bivalvia (clams, cockles, mussels, oysters and scallops) Cephalopoda (octopuses, squids, cuttlefish and nautiluses) Gastropoda (snails and slugs) Monoplacophora Polyplacophora (chitons, or sea cradles) Scaphopoda (tusk shells)
Nematoda (roundworms) Chromadorea Enoplea
Nematomorpha (horsehair worms) Gordioida Nectonematoida
Nemertea (ribbon worms) Hoplonemertea Palaeonemertea Pilidiophora
Placozoa Polyplacotomia Uniplacotomia
Platyhelminthes (flatworms) Catenulida Turbellaria (e.g. Dugesia, paraphyletic with respect to Neodermata) Neodermata (parasitic worms) Cestoda (tapeworms and relatives) Monogenea Trematoda (flukes)
Porifera (sponges) Calcarea (calcareous sponges) Demospongiae Hexactinellida (glass sponges) Homoscleromorpha
Priapulida (priapulid worms) Halicryptomorpha Priapulimorpha Seticoronaria
Rotifera (rotifers) Bdelloidea Monogononta Seisonidea Acanthocephala (thorny-headed worms) Source: Archiacanthocephala Eoacanthocephala Palaeacanthocephala (ancient thornheads) Polyacanthocephala
Tardigrada (tardigrades, water bears, or moss piglets) Eutardigrada Heterotardigrada
Xenacoelomorpha Acoelomorpha (simple soft-bodied flat worms) Acoela Nemertodermatida
References