Family (biology)

taxonomic rank (or a taxon at that rank) between order and genus

In biology, a family is a taxonomic rank. Each family contains one or more genera. The next higher rank is that of order.

A hierarchy of important ranks

Usually, the name of the family ends with a "idae" for animals, and "aceae" for plants. Sometimes there are also subfamilies and superfamilies. Subfamilies end with "inae" or "oideae".

For example, walnuts (genus Juglans) and hickories (genus Carya) both belong to the walnut family (the Juglandaceae).

Life is the most important concept in biology. The word itself refers to a living being or to its processes. It may mean the time a being is alive.



A domain is the highest taxonomic rank of all living organisms taken together. It was introduced in the three-domain system of taxonomy by Carl Woese, Otto Kandler and Mark Wheelis in 1990.



Kingdom is the highest level of classification, which is divided into subgroups at various levels. There are five kingdoms in which the living organisms are classified, namely, Animalia, Plantae, Fungi, Protista, and Monera.



Phylum is the next level of classification and is more specific than the kingdom. There are 35 phyla in kingdom Animalia. For Example – Porifera, Chordata, Arthropoda, etc.

Class was the most general rank in the taxonomic hierarchy until phyla were introduced. Kingdom Animalia includes 108 classes including class Mammalia, Reptilia, Aves, etc. However, the classes used today are different from those proposed by Linnaeus and are not used frequently. For example, when it was discovered that birds are descendants of earlier dinosaurs, that caused some difficulties. In fact they are now so different from the original dinosaurs that it makes sense to teach and refer to them separately from dinosaurs.

Order is a more specific rank than class. The order constitutes one or more than one similar families. There are around 26 orders in class Mammalia such as Primates, Carnivora, etc.



Family is a category of taxonomic hierarchy includes various genera that share a few similarities. For e.g., the families in the order Carnivora include Canidae, Felidae, Ursidae, etc.

A genus is a group of similar species. Some genera have only one species and are known as monotypic, whereas others have more than one species and are known as polytypic. For example, lion and tiger are placed under the genus Panthera



Species is the lowest level of taxonomic hierarchy. There are about 8.7 million different species on Earth. The word refers to a group of organisms that are similar in shape, form, reproductive features. Species can be further divided into sub-species.