The world of organic life has been divided into the plant and animal
kingdoms. These kingdoms have been further divided into larger divisions
called _phyla_ (from the Greek word _phylon_, a race). Each phylum is
composed of organisms with certain characteristics in common. For
example, all animals with a spinal cord (or notochord) are assigned to
the phylum Chordata.
The phylum is reduced to smaller divisions called _classes_, classes are
divided into _orders_, orders into _families_, families into _genera_,
and each genus is divided into still smaller units called _species_. A
species may be further reduced to subspecies, varieties, or other
subspecific categories, but these need not concern us in a publication
of this nature.
The following table illustrates the use of binomial nomenclature in the
classification of man, a clam, and a dog.
Unit Man Dog Clam
Kingdom Animalia Animalia Animalia
Phylum Chordata Chordata Mollusca
Class Mammalia Mammalia Pelecypoda
Order Primates Carnivora Eulamellibranchia
Family Hominidae Canidae Veneridae
Genus _Homo_ _Canis_ _Venus_
Species _sapiens_ _familiaris_ _mercenaria_
The generic name and the trivial name constitute the _scientific name_
of a species and according to this system of classification the
scientific name of all living men is _Homo sapiens_. It is obvious that
there are many variations among individual men, but all men have certain
general characteristics in common and are therefore placed in the same
species.
In a scientific name, the generic name is always started with a capital
letter and the trivial name with a small letter. Both names must be
italicized or underlined.
The name of the author (the person who first described the fossil)
usually appears following the scientific name. The date of the
scientific publication containing the original description of the fossil
is often placed after the author. For example:
_Turrilites worthensis_ Adkins and Winton 1920
With the large numbers of plants and animals that are living today, plus
those of the past, random naming would result in much confusion. For
this reason scientists have established strict rules that must be
followed when a specimen is named. The strict application of these rules
enables scientists in all parts of the world to assign scientific names
without fear of duplication.