The taxonomy of invertebrates as proposed by Richard C. Brusca and Gary J. Brusca in 2003 is a system of classification with emphasis on the invertebrates, in other words, a way to classify animals, primarily those which have no backbone.
Kingdom Eubacteria (Bacteria)Kingdom Archaea (Archaebacteria)Kingdom FungiKingdom Plantae (= Metaphyta)Kingdom ProtistaPhylum Porifera
Phylum PoriferaPhylum PlacozoaPhylum Monoblastozoa
Phylum MonoblastozoaPhylum Rhombozoa
Phylum RhombozoaPhylum OrthonectidaRadiata
Phylum CnidariaPhylum CtenophoraBilateria
The authors divide the bilaterians in three informal groups:
acoelomates (phyla Platyhelminthes, Gastrotricha, Entoprocta, Gnathostomulida, Cycliophora)blastocoelomate (or pseducoelomate, phyla Rotifera, Kinorhyncha, Nematoda, Nematomorpha, Acanthocephala, Loricifera)coelomates (or eucoelomates, phyla Nemertea, Priapula, Annelida, Sipuncula, Echiura, Onychophora, Tardigrada, Arthropoda, Mollusca, Phoronida, Ectoprocta, Brachiopoda, Echinodermata, Chaetognatha, Hemichordata, Chordata).Several groups traditionally viewed as having a blastocoelomate condition are viewed here as acoelomates (e.g., Gastrotricha, Entoprocta, Gnathostomulida).
Some of the coelomates groups (e.g., Arthropoda, Mollusca) have greatly reduced celomic spaces; often the main body cavity is a bloodfilled space called a hemocoel, and is associated with an open circulatory system.
The Brachiopoda, Ectoprocta and Phoronida are viewed as lophophorates.
In a phylogeny, the bilaterians are divided in:
ProtostomiaDeuterostomiaPhylum Platyhelminthes
Phylum PlatyhelminthesPhylum NemerteaPhylum Rotifera
Phylum RotiferaPhylum Gastrotricha
Phylum GastrotrichaPhylum KinorhynchaPhylum Nematoda (= Nemata)
Phylum Nematoda (= Nemata)Phylum NematomorphaPhylum Priapula
Phylum PriapulaPhylum AcanthocephalaPhylum Entoprocta (= Kamptozoa)
Phylum Entoprocta (= Kamptozoa)Phylum Gnathostomulida
Phylum GnathostomulidaPhylum LoriciferaPhylum Cycliophora
Phylum CycliophoraPhylum Annelida
Phylum AnnelidaPhylum SipunculaPhylum EchiuraPhylum OnychophoraPhylum Tardigrada
Phylum TardigradaPhylum Arthropoda
Phylum ArthropodaPhylum Mollusca
Phylum MolluscaPhylum Phoronida
Phylum PhoronidaPhylum Ectoprocta (= Bryozoa)
Phylum Ectoprocta (= Bryozoa)Phylum Brachiopoda
Phylum BrachiopodaPhylum Echinodermata
Phylum EchinodermataPhylum ChaetognathaPhylum Hemichordata
Phylum HemichordataPhylum Chordata
Phylum Chordata 