# Animal Phyla

A Phylum (pl. Phyla) is the largest formal major grouping within animal taxonomy. This list is presented in alphabetical order, and not in any systematic/evolutionary arrangement. This list is also available in table form. Science is by no means static. There are arguments of all sizes and shapes about the taxonomy of the Animal Phyla. Other sources may combine or split these listed Phyla. However, at this time, the list presented here should stand in good stead for an introduction to the topic of animal diversity.
There are approximately 1.9 million animal species that have been described by science.
This list tries to give the following information on each Phylum:
* Phyllum Name
* A link to a sub-page discussing that Phylum in more detail (if it yet exists)
* Name Meaning (in English)
* An English Common Name, where one is in regular use
* Distinguishing characteristics of animals within the Phylum
* An approximate number of species described within that Phylum. Since zoology fortunately refuses to stand move, this number can change.
Oh! And there's a quiz at the end. See also Lesson Plan for Animal Phyla. Or head to Introduction_to_Taxonomy for more on that topic. You can also visit Plant Divisions (Phyla), the equivalent page for plants.

## Acanthocephalae

Acanthocephala
Name Meaning: Thorny head
English Common Name: Thorn-headed worms
Major distinguishing characteristics: Reversible spiny proboscis
Approximate number of species described: 1,151

## Acoelomorpha

Acoelomorpha
Name Meaning: Without gut
English Common Name: Acoels
Major distinguishing characteristics: No mouth or alimentary canal
Approximate number of species described: 50,000

## Annelida

Annelida
Name Meaning: Little ring
English Common Name: Segmented worms, annelids
Major distinguishing characteristics: Multiple circular segments
Approximate number of species described: 22,000 modern

## Arthropoda

Arthropoda
Name Meaning: Jointed foot
English Common Name: Arthropods
Major distinguishing characteristics: Chitin exoskeleton
Approximate number of species described: 1,134,000+

## Brachiopoda

Brachiopoda
Name Meaning: Arm foot
English Common Name: Lamp shells, brachiopod
Major distinguishing characteristics: Lophophore and pedicle
Approximate number of species described: between 300 and 500 extant

## Bryozoa

Bryozoa
Name Meaning: Moss animals
English Common Name: Moss animals, sea mats, bryozoans
Major distinguishing characteristics: Lophophore, no pedicle, ciliated tentacles
Approximate number of species described: about 5,000 living species

## Chaetognatha

Chaetognatha
Name Meaning: Longhair jaw
English Common Name: Arrow worms
Major distinguishing characteristics: Chitinous spines either side of head, fins
Approximate number of species described: about 100 modern species

## Chordata

Chordata
Name Meaning: Cord
English Common Name: Chordates
Major distinguishing characteristics: Hollow dorsal nervous chord
Approximate number of species described: about 100,000+

## Cnidaria

Cnidaria
Name Meaning: Stinging nettle
English Common Name: Coelenterates, cnidarians, sea anemones, jellies, hydra
Major distinguishing characteristics: Cnidocytes (stinging cells)
Approximate number of species described: about 11,000

## Ctenophora

Ctenophora
Name Meaning: Comb bearer
English Common Name: Comb jellies, Ctenophores
Major distinguishing characteristics: Eight "comb rows" of fused cilia
Approximate number of species described: about 100 modern species

## Cycliophora

Cycliophora
Name Meaning: Wheel carrying
English Common Name: Symbion
Major distinguishing characteristics: Circular mouth surrounded by small cilia
Approximate number of species described: at least 3

## Echinodermata

Echinodermata
Name Meaning: Spiny skin(Body)
English Common Name: Echinoderms
Major distinguishing characteristics: Five-fold radial symmetry, mesodermal layer, calcified spines
Approximate number of species described: about 7,000 living species and 13,000 extinct ones

## Entoprocta

Entoprocta
Name Meaning: Inside anus
English Common Name: Goblet worm
Major distinguishing characteristics: Anus inside ring of cilia
Approximate number of species described: about 150

## Gastrotricha

Gastrotricha
Name Meaning: Hair stomach
English Common Name: Hairybellies, hairybacks
Major Distinguishing Characteristics: Two terminal adhesive tubes
Approximate number of species described: about 690

## Gnathostomulida

Gnathostomulida
Name Meaning: Jaw orifice
English Common Name: Jaw worms
Major distinguishing characteristics:
Approximate number of species described: about 100

## Hemichordata

Hemichordata
Name Meaning: Half cord
English Common Name: Acorn worms
Major distinguishing characteristics: Stomochord in collar
Approximate number of species described: about 100 living species

## Kinorhyncha

Kinorhyncha
Name Meaning: Motion snout
English Common Name: Mud dragons
Major distinguishing characteristics: Eleven segments, each with a dorsal plate
Approximate number of species described: about 150

## Loricifera

Loricifera
Name Meaning: Corset bearer
English Common Name: Loriciferans
Major distinguishing characteristics: Umbrella-like scales at each end
Approximate number of species described: about 122

## Micrognathozoa

Micrognathozoa (sometimes called Phylum Gnathifera)
Name Meaning: Tiny jaw animals
English Common Name: Micrognathozoans
Major distinguishing characteristics: Accordion like extensible thorax
Approximate number of species described: 1

## Mollusca

Mollusca
Name Meaning: Thin shell
English Common Name: Mollusks or molluscs
Major distinguishing characteristics: Muscular foot and Mantle, round shell
Approximate number of species described: 85,000

## Nematoda

Nematoda
Name Meaning: Thread like
English Common Name: Round worms, Nematodes
Major distinguishing characteristics: Round cross section, keratin, cuticle
Approximate number of species described: 80 000 - 1 million

## Nematomorpha

Nematomorpha
Name Meaning: Thread form
English Common Name: Horsehair worms
Major distinguishing characteristics:
Approximate number of species described: about 320

## Nemertea

Nemertea
Name Meaning: A sea nymph
English Common Name: Ribbon worms
Major distinguishing characteristics:
Approximate number of species described: about 1200

## Onychophora

Onychophora
Name Meaning: Claw bearer
English Common Name: Velvet worms
Major distinguishing characteristics: Legs tipped by chitinous claws
Approximate number of species described: about 200 modern

## Orthonectida

Orthonectida
Name Meaning: Straight swim
English Common Name: Orthonectida
Major distinguishing characteristics:
Approximate number of species described: about 20

## Phoronida

Phoronida
Name Meaning: Zeus' mistress
English Common Name: Horseshoe worms
Major distinguishing characteristics: U-shaped gut
Approximate number of species described: 20

## Placozoa

Placozoa
Name Meaning: Plate animals
English Common Name: none
Major distinguishing characteristics:
Approximate number of species described: 1

## Platyhelminthes

Platyhelminthes
Name Meaning: Flat worms
English Common Name: Flat worms
Major distinguishing characteristics:
Approximate number of species described: about 25,000

## Porifera

Porifera
Name Meaning: Pore bearer
English Common Name: Sponges
Major distinguishing characteristics: Perforated interior wall
Approximate number of species described: over 5,000 modern

## Priapulida

Priapulida
Name Meaning: Penis
English Common Name: Priapulid worms
Major distinguishing characteristics: Retractable proboscis surrounded by papillae
Approximate number of species described: 17

## Rhombozoa

Rhombozoa
Name Meaning: Rhombus animal
English Common Name: Rhombozoans
Major distinguishing characteristics: Single axial cell surrounded by ciliated cells
Approximate number of species described: 75

## Rotifera

Rotifera
Name Meaning: Wheel bearer
English Common Name: Rotifers
Major distinguishing characteristics: Anterior crown of cilia
Approximate number of species described: about 2000

## Tardigrada

Tardigrada
Name Meaning: Slow step
English Common Name: Water bears
Major distinguishing characteristics: Four segmented body and head
Approximate number of species described: 1,000+

## Xenoturbellida

Xenoturbellida
Name Meaning: Strange flatworm
English Common Name: none
Major distinguishing characteristics: Ciliated deuterostome
Approximate number of species described: 2

## Quizzes

* Animal Phyla Quiz