Phylum Meaning Group Distinguishing characteristics Species described
Acanthocephala Thorny head Thorny-headed worms Reversible spiny proboscis about 1,151
Acoelomorpha Without gut Acoels No mouth or alimentary canal
Annelida Little ring Segmented worms Multiple circular segments about 15,000 modern
Arthropoda Jointed foot Arthropods Chitin exoskeleton 1,134,000+
Brachiopoda Arm foot Lamp shells Lophophore and pedicle between 300 and 500 extant
Bryozoa Moss animals Moss animals, sea mats Lophophore, no pedicle, ciliated tentacles about 5,000 living species
Chaetognatha Longhair jaw Arrow worms Chitinous spines either side of head, fins about 100 modern species
Chordata Cord Chordates Hollow dorsal nervous chord about 100,000+
Cnidaria Stinging nettle Coelenterates Nematocysts (stinging cells) about 11,000
Ctenophora Comb bearer Comb jellies Eight "comb rows" of fused cilia about 100 modern species
Cycliophora Wheel carrying Symbion Circular mouth surrounded by small cilia at least 3
Echinodermata Spiny skin Echinoderms Five-fold radial symmetry, mesodermal layer, calcified spines about 7,000 living species and 13,000 extinct ones
Echiura Spine tail Spoon worms Set of hooks at posterior end about 140
Entoprocta Inside anus Goblet worm Anus inside ring of cilia about 150
Gastrotricha Hair stomach Meiofauna Two terminal adhesive tubes about 690
Gnathostomulida Jaw orifice Jaw worms about 100
Hemichordata Half cord Acorn worms Stomochord in collar about 100 living species
Kinorhyncha Motion snout Mud dragons Eleven segments, each with a dorsal plate about 150
Loricifera Corset bearer Brush heads Umbrella-like scales at each end about 122
Mesozoa Middle animals Mesozoans Somatoderm of ciliated cells surrounding reproductive cell(s)
Micrognathozoa Tiny jaw animals Accordion like extensible thorax 1
Mollusca Thin shell Mollusks / molluscs Muscular foot and Mantle, round shell 112,000[1]
Myxozoa Slime animals Polar capsules resembling nematocysts 13,000+
Nematoda Thread like Round worms Round cross section, keratin, cuticle 80 000 - 1 million
Nematomorpha Thread form Horsehair worms about 320
Nemertea A sea nymph Ribbon worms about 1200
Onychophora Claw bearer Velvet worms Legs tipped by chitinous claws about 200 modern
Orthonectida Straight swim about 20
Phoronida Zeus' mistress Horseshoe worms U-shaped gut 20
Placozoa Plate animals 1
Platyhelminthes Flat worms Flat worms about 25,000[2]
Porifera Pore bearer Sponges Perforated interior wall over 5,000 modern
Priapulida Penis Priapulid worms Retractable proboscis surrounded by papillae 17
Rhombozoa Lozenge animal Single axial cell surrounded by ciliated cells 75
Rotifera Wheel bearer Rotifers Anterior crown of cilia about 2000
Sipuncula Small tube Peanut worms Mouth surrounded by invertible tentacles 144-320
Tardigrada Slow step Water bears Four segmented body and head 1,000+
Xenoturbellida Strange flatworm Ciliated deuterostome 2
TOTAL 2,000,000-

References

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  1. Feldkamp, S. (2002) Modern Biology. Holt, Rinehart, and Winston, USA. (pp. 725)
  2. Species Register. "Flatworms - Phylum Platyhelminthes". Marine Discovery Centres. Retrieved 2007-04-09.