Phylum (biology)
From Freepedia
Phylum (plural: phyla) is a taxon used in the classification of animals, adopted from the Greek phylai the clan-based voting groups in Greek city-states. (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 (e.g. Ecdysozoa with eight phyla, including arthropods and roundworms, and Deuterostomia with the echinoderms, chordates, hemichordates and arrow worms).
The best known animal phyla are the Mollusca, Porifera, Cnidaria, Platyhelminthes, Nematoda, Annelida, Arthropoda, Echinodermata, and Chordata, the phylum humans belong to... Although there are approximately 35 phyla, these nine include the majority of the species. Although many phyla are exclusively marine, only one phylum is entirely absent from the world's oceans: the Onychophora or velvet worms.
External links
- 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"
