Phylum

http://bioontology.org/projects/ontologies/birnlex#birnlex_7086

false

In biological taxonomy, a phylum (Greek ????? plural: ???? phyla) is a taxon in the rank below kingdom and above class. "Phylum" is adopted from the Greek ????? phylai, the clan-based voting groups in Greek city-states. Phyla represent the largest generally accepted groupings of animals and other living things 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). Informally, phyla can be thought of as grouping animals based on general body plan[1]; this is morphological grouping. Thus despite the seemingly different external appearances of organisms, they are classified into phyla based on their internal organizations[2]. For example, though seemingly divergent, spiders and crabs both belong to Arthropoda, whereas earthworms and tapeworms, similar in shape, are from Annelida and Platyhelminthes, respectively. Although the International Code of Botanical Nomenclature allows the use of the term "Phylum" in reference to plants, the term "Division" is almost always used by botanists.The Cambrian explosion was a great flowering of life forms that occurred between roughly 530 and 520 million years ago;[4] during this time organisms similar to, but not strictly members of, modern phyla existed;[5] whilst some appear to be represented in the Ediacaran biota, it remains a matter of debate whether all phyla existed prior to the explosion. Over time the roles among different phyla have varied. For instance, during the Cambrian, the dominant megafauna, or large animals, were arthropods, whereas now the megafauna is dominated by vertebrates (chordata).[6] The arthropods are still by far the most dominant phylum.

Phylum

2007-06-03

Phylum

birnlex_7086

Phylum

false

http://bioontology.org/projects/ontologies/birnlex#birnlex_591