Holotype

Definition

The single physical specimen designated as the name-bearing type when a species is formally described, serving as the objective reference for the species name under the International Code of Zoological Nomenclature (ICZN). The holotype anchors the species concept: if subsequent specimens differ, the holotype's morphology determines which population bears the original name. In zoology, it is one of several name-bearing types; botanists use parallel but not identical terminology under the ICN.

Etymology

From Greek holos (whole, complete) + typos (mark, impression, model)

Example

When Chamberlin described the millipede genus Zantaenia in 1941, he designated a single specimen as the holotype; all subsequent comparisons of Zantaenia species must reference that individual's morphology.

Synonyms

• name-bearing type
• Type specimen

Related Terms

• Paratype
• lectotype
• neotype
• syntype
• type locality
• type series
• International Code of Zoological Nomenclature
• species description

Usage Notes

A holotype is explicitly designated by the original author in the species description; it is not merely the first specimen collected. If the original description lacks a designated holotype, later authors may select a lectotype from the syntype series. The holotype is typically deposited in a permanent museum collection with full collection data. Contrast with paratypes (other specimens cited in the original description) and topotypes (subsequent specimens from the type locality).