epitype

An epitype is a specimen or illustration designated to serve as an interpretative type to fix the application of a zoological or botanical name when the original type material is insufficient to determine the defining features of the taxon. It is used to clarify how the name should be applied in cases where the holotype, lectotype, or syntypes do not provide enough diagnostic information.

Designation of an epitype occurs when the existing type material cannot unambiguously determine the taxon's identity, typically because it lacks key characters, is damaged, or only a general description is available. The designation is made in a published work and includes a justification that the original material is inadequate for precise interpretation and a statement of how the epitype clarifies the name’s application. The epitype should be consistent with the taxon concept as understood at the time and with the features described for the name.

An epitype is supplementary to the existing type and does not replace it. It provides additional reference material that helps link the name to observable characteristics, allowing current taxonomic concepts to be applied more reliably. The epitype can be a physical specimen or an illustration and is typically designated to align with the diagnostic features used to define the taxon, including imaging or morphological details that were not captured by the original type.

In practice, epitypes play a corrective role, enabling stable naming when original material is ambiguous while preserving the primacy of the established type.