Family (biology)

related topics
{specie, animal, plant}
{language, word, form}
{theory, work, human}
{math, number, function}
{rate, high, increase}

In biological classification, family (Latin: familia) is

  • a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the prefix sub-: subfamily (Latin: subfamilia).
  • a taxonomic unit, a taxon, in that rank. In that case the plural is families (Latin familiae)

What does and does not belong to each family is determined by a taxonomist. Similarly for the question if a particular family should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing a family. Some taxa are accepted almost universally, while others are recognised only rarely.

Contents

History of the concept

Family, as a rank intermediate between order and genus, is a relatively recent invention.

The taxonomic term familia was first used by French botanist Pierre Magnol in his Prodromus historiae generalis plantarum, in quo familiae plantarum per tabulas disponuntur (1689) where he called the seventy-six groups of plants he recognised in his tables families (familiae). The concept of rank at that time was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera, which is far from how the term is used today.

Carolus Linnaeus used the word familia in his Philosophia botanica (1751) to denote major groups of plants: trees, herbs, ferns, palms, and so on. He used this term only in the morphological section of the book, discussing the vegetative and generative organs of plants. Subsequently, in French botanical publications, from Michel Adanson's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille was used as a French equivalent of the Latin ordo (or ordo naturalis). In nineteenth century works such as the Prodromus of Augustin Pyramus de Candolle and the Genera Plantarum of George Bentham and Joseph Dalton Hooker this word ordo was used for what now is given the rank of family.

Full article ▸

related documents
Linnaean taxonomy
Vampyrellid
List of cryptids
Cuculiformes
Boraginaceae
Chow Chow
Porcupinefish
XY sex-determination system
Commelinales
Dsungaripterus
Haptophyte
Okapi
Salvinia molesta
Boidae
List of birds
Canellales
Lamiales
Euglena
Actinopterygii
Chlorophyta
Homininae
Equisetum
Sainfoin
Coelom
Bison
Thrush Nightingale
Mesoderm
Ceiba
Psilocybe cubensis
Gaillardia