The
phylum is the second highest ranking of animals in standard scientific
taxonomy, and is equivalent to 'Division" for Plants and
Bacteria. The original Linnaean taxonomy did not define nor have
phyla (plural), and the term was ntroduced by Ernst Haeckel. A
Phylum is the taxonomic category between Kingdom and Class, 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 Some traditional Phyla like the Protozoa are no longer
valid (polyphyletic). According
to Bengstrom (1986),
a "typical" phylum is a group of organisms of uncertain
(or problematic) taxonomic affinities.
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