Minor Animal Phyla

The rotifers (, from Latin rota 'wheel' and -fer 'bearing'), sometimes called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic pseudocoelomate animals.

Tardigrades ( ), also known as water bears or moss piglets, are a phylum of eight-legged segmented micro-animals.

Nemertea is a phylum of animals also known as ribbon worms or proboscis worms, consisting of about 1300 known species.

Hemichordata ( HEM-ih-kor-DAY-tə) is a phylum which consists of triploblastic, eucoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms.

Priapulida (priapulid worms, from Gr. πριάπος, priāpos 'Priapus' + Lat.

Xenacoelomorpha () is a small phylum of bilaterian invertebrate animals, consisting of two sister groups: acoelomorphs and xenoturbellids.

Kinorhyncha (Ancient Greek: κινέω, romanized: kīnéō, lit.

Entoprocta (lit. 'inside rectum/anus'), or Kamptozoa , commonly called goblet worms, is a phylum of mostly-sessile aquatic animals, ranging from 0.1 to 7 millimetres (0.004 to 0.3 in) long.

Placozoa ( PLAK-ə-ZOH-ə; lit. 'flat animals') is a phylum of free-living (non-parasitic) marine invertebrates.

Gnathostomulids, or jaw worms, are a small phylum of nearly microscopic marine animals.

Limnognathia is a genus of microscopic acoelomate freshwater animal that was discovered in Disko Island, Greenland, in 1994.

Nematomorpha (sometimes called Gordiacea, and commonly known as horsehair worms, hairsnakes, or Gordian worms) are a phylum of parasitoid animals similar to yet distinct from nematode worms in morphology, hence the name.

Orthonectida () is a small phylum of poorly known parasites of marine invertebrates that are among the simplest of multi-cellular organisms.

Dicyemida, also known as Rhombozoa, is a phylum of tiny parasites that live in the renal appendages of cephalopods.

Onychophora (from Ancient Greek: ονυχής, onyches, "claws"; and φέρειν, pherein, "to carry"), commonly known as velvet worms (for their velvety texture and somewhat worm-like appearance), is a phylum of long, soft-bodied, many-legged animals.

The Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies.

Loricifera (from Latin, lorica, corselet (armour) + Latin fero, to carry or bear), also known as corset animals, is a phylum of very small to microscopic marine scalidophoran sediment-dwelling animals with 44 described species and approximately 100 more that have been collected and not yet described.

Phoronids (taxonomic name Phoronida, sometimes called horseshoe worms) are a small phylum of marine animals that filter-feed with a lophophore (a "crown" of tentacles), and build upright tubes of chitin to support and protect their soft bodies.

Symbion is a genus of commensal aquatic animals, less than 0.5 mm wide, found living attached to the mouthparts of cold-water lobsters.

Acanthocephala (Greek ἄκανθος, akanthos 'thorn' + κεφαλή, kephale 'head') is a group of parasitic worms known as acanthocephalans, thorny-headed worms, or spiny-headed worms, characterized by the presence of an eversible proboscis, armed with spines, which it uses to pierce and hold the gut wall of its host.

The Chaetognatha or chaetognaths (meaning bristle-jaws) are a phylum of predatory marine worms that are a major component of plankton worldwide.

The gastrotrichs (phylum Gastrotricha), commonly referred to as hairybellies or hairybacks, are a group of microscopic (0.06-3.0 mm), cylindrical, acoelomate animals, and are widely distributed and abundant in freshwater and marine environments.

Brachiopods (), phylum Brachiopoda, are a phylum of animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs.

Ctenophora (; from Ancient Greek κτείς (kteis) 'comb' and φέρω (pherō) 'to carry') or ctenophores (), commonly known as comb jellies, is a basal phylum of marine invertebrate animals notable for their unique aquatic locomotion using groups of cilia (commonly referred to as "combs").