In biology, the classification of organisms into a hierarchy of groupings, from the general to the particular, that reflect evolutionary and usually morphological relationships: kingdom, phylum, class, order, family, genus, species .
The black-capped chickadee, for example, is an animal (kingdom Animalia) with a dorsal nerve cord (phylum Chordata) and feathers (class Aves: birds) that perches (order Passeriformes: perching birds) and is small with a short bill (family Paridae), a song that sounds like "chik-a-dee" (genus Parus ), and a black-capped head (species atricapillus ). Most authorities recognize five kingdoms: monerans ( protists , fungi (see fungus ), {{link=plant">plants , and animals . Carolus Linnaeus established the scheme of using Latin generic and specific names in the mid-18th century; his work was extensively revised by later biologists.