Phylum
From Palaeos
| Linnaean taxonomy |
| Kingdom | Phylum | Class | Order | Family | Tribe | Genus | Species |
The second highest ranking of animals in the standard scientific taxonomy, referred to as 'Division" in the case of Plants and Bacteria. There was no "phylum" in the original Linnaean taxonomy; the word was introduced by Ernst Haeckel. A Phylum is the taxonomic category between Kingdom and Class. A phylum is a major ranking of organisms, defined according to the most basic body-parts shared by that group. e.g. Chordata (animals with a notochord - vertebrates and others), Arthropoda (animals with a jointed exoskeleton) Mollusca (animals with a rasping radula and shell-secreting mantle), Angiospermae (flowering plants), and so on. Some traditional Phyla like the Protozoa are invalid (polyphyletic).
The operational meaning of phylum is more illuminated if we consider that a "typical" phylum is a group of organisms of uncertain (or problematic) taxonomic affinities (see Bengstrom, 1986.
[edit] References
Bengtson, S. (1986) The problem of the Problematica. In Problematic Fossil Taxa, Vol. 5 (Eds, Hoffman, A. & Nitecki, M.H.) Oxford U. P., N.Y., & Clarendon, Oxford, pp. 3-11.
Palaeos com - Phylum
Credits: Palaeos com MAK020520, copied Palaeos org MAK060929
