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 the Latin genus meaning "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 genera:
“Genius detects through the fly, through the caterpillar, through the grub, through the egg, the constant individual; through countless individuals the fixed species; through many species the genus; through all genera the steadfast type; through all the kingdoms of organized life the eternal unity. Nature is a mutable cloud which is always and never the same.”
—Ralph Waldo Emerson (18031882)