idae

idae is a taxonomic suffix used in zoological nomenclature to form the names of families within the animal kingdom. It is attached to a stem, often derived from a genus name or a characteristic, to indicate the family rank in the classification system governed by the International Code of Zoological Nomenclature (ICZN).

Examples of families ending in -idae include Canidae (dogs), Felidae (cats), Ursidae (bears), Hominidae (great apes and humans), Formicidae (ants), and Vespidae (a family of wasps). In many groups, such as mammals, birds, insects, and arachnids, the family name is created by taking the root from a representative genus or trait and adding -idae.

Notes: -idae denotes a family-level taxon in animals; plant and alga taxonomy uses the suffix -aceae for families, not -idae. The naming rules are governed by the ICZN; family names are typically capitalized and treated as formal scientific names. There are historical exceptions to stem formation, and some families retain traditional names that do not transparently reflect their type genus.

In classification, -idae is one of several standard suffixes for designated ranks (for example -inae for subfamilies and -oidea for superfamilies). This suffix helps indicate the rank and group membership of diverse animal lineages across many phyla.