List of animal classes

Template:Short description Script error: No such module "Labelled list hatnote". The following is a list of the classes in each phylum of the kingdom Animalia. There are 107 classes of animals in 33 phyla in this list. 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.

Acanthocephala (thorny-headed worms)

Archiacanthocephala
Eoacanthocephala
Palaeacanthocephala (ancient thornheads)
Polyacanthocephala

Acoelomorpha (simple soft-bodied flatworms)

Annelida (segmented worms)

Clitellata (earthworms, leeches)
Polychaeta (bristle worms)
Sipuncula (peanut worms)

Arthropoda (arthropods: insects, crustaceans, arachnids, centipedes, and millipedes)

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Chelicerata

Source:^[1]

Arachnida (spiders, scorpions, and kin)
Xiphosura (horseshoe crabs)
Pycnogonida (sea spiders)

Crustacea

Source:^[2]

Branchiopoda (fairy shrimp, tadpole shrimp, water fleas, and clam shrimp)^[3]
Cephalocarida (horseshoe shrimp)^[4]
Pentastomida (tongue worms)
Branchiura (fish lice)
Mystacocarida
Copepoda
Ostracoda (seed shrimp)^[5]
Malacostraca (crabs, lobsters, crayfish, krill, various shrimp, woodlice, and kin)^[6]
Thecostraca (barnacles)
Remipedia

Hexapoda

Source:^[7]

Entognatha (coneheads, two-pronged bristletails and springtails)
Insecta (insects)

Myriapoda

Source:^[8]

Chilopoda (centipedes)
Diplopoda (millipedes)
Pauropoda
Symphyla (pseudocentipedes)

Brachiopoda ("lamp shells")

Bryozoa (moss animals)

Chaetognatha (arrow worms)

Sagittoidea

Chordata (vertebrates, tunicates, and lancelets)

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Cephalochordata

Leptocardii (lancelet)

Tunicata

Appendicularia (larvaceans)
Ascidiacea (sea squirts, paraphyletic with respect to Thaliacea)
Thaliacea (salps, pyrosomes, and doliolids)

Myxini (hagfish)
Petromyzontida (lamprey)

Gnathostomata

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)