In biology, a genus (plural: genera) is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia. Genera and higher taxonomic levels such as families are used in biodiversity studies, particularly in fossil studies since species cannot always be confidently identified and genera and families typically have longer stratigraphic ranges than species.
The term comes from Latin genus "descent, family, type, gender", cognate with Greek: γένος – genos, "race, stock, kin".
The composition of a genus is determined by a taxonomist. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. In the hierarchy of the binomial classification system, genus comes above species and below family.
Famous quotes containing the word genus:
“Methinks it would be some advantage to philosophy if men were named merely in the gross, as they are known. It would be necessary only to know the genus and perhaps the race or variety, to know the individual. We are not prepared to believe that every private soldier in a Roman army had a name of his own,because we have not supposed that he had a character of his own.”
—Henry David Thoreau (18171862)