Phylum (biology)

Phylum (plural: phyla) is a taxonomic rank used in the classification of animals. (Although the International Code of Botanical Nomenclature allows the use of the term "Phylum", the term "Division" is almost always used by botanists.) Phyla represent the largest generally accepted groupings of animals with certain evolutionary traits, although the phyla themselves may sometimes be grouped into superphyla.

The best known animal phyla are the Mollusca, Porifera, Cnidaria, Platyhelminthes, Nematoda, Annelida, Arthropoda, Echinodermata, and Chordata, our own phylum. Although there are approximately 35 phyla, these nine include the majority of the species. Members of every phylum inhabit the world's oceans except one – the Onychophora or velvet worms.

External links (etymology)

• American Heritage Dictionary: New Latin phylum, from Greek phūlon, class.
• Online Etymological Dictionary: from Gk. phylon "race, stock," related to phyle "tribe, clan," and phylein "bring forth" of physikos "pertaining to nature," from physis "nature"