International Commission on Zoological Nomenclature

Declaration 45 - Addition of Recommendations to Article 73 and of the term “specimen, preserved” to the Glossary


  1. The following Recommendations are added to read:
    a) “Recommendation 73G. Specific reasons for designation of an unpreserved specimen as the name-bearing type. An author should provide detailed reasoning why at least one preserved specimen, whether a complete individual organism or a part of such an individual, was not used as the name-bearing type for the new taxon and why the formal naming of the taxon is needed at a point in time when no preserved name-bearing type will be available.”
    b) “Recommendation 73H. Assertion of due diligence. When establishing a new species-group taxon without a preserved name-bearing type, steps taken by an author to capture and preserve a physical specimen of the new taxon and/or locate an existing preserved specimen in natural history collections should be recounted.”
    c) “Recommendation 73I. Consultation with specialists. Before the designation ofan unpreserved specimen as a name-bearing type, an author should consult with specialists in the group in question.”
    d) “Recommendation 73J. Comprehensive iconography and measurements. When establishing a new species-group taxon without a preserved name-bearing type, the author should provide extensive documentation (e.g., multiple original high-resolution images, DNA sequences, etc.) of potentially diagnostic characters as completely as possible.”
  2. The following term is added to the Glossary under the term “specimen” to read: “specimen, preserved. A non-living specimen that is deposited in a scientific collection with the intention to keep it for further study.”

Explanatory note

Whenever feasible, new species-group taxa should be established on the basis of at least one preserved type specimen. Additional information representing diagnostic characters (e.g., illustrations, DNA sequences, audio recording analyses, etc.) should accompany the description of a new species-group taxon whenever possible, but well-preserved biological specimens (either as complete individuals, or parts of individuals) are widely regarded as representing the most generally reliable means for establishing the biological and scientific basis for a species-group name. Establishing new species-group taxa without preserved name-bearing type material is permissible under the Code, but is discouraged unless justified by special circumstances, such as when capture or preservation of specimens is not feasible for technical reasons or for conservation concerns, or when specimens must be destroyed to reliably diagnose a new species. While preserving a whole organism as the type specimen is preferable and encouraged, in circumstances when whole organism preservation is not feasible a portion (or portions) of the organism sufficient to allow the new species-group taxon to be reliably diagnosed should be preserved. 


On 2 May 2016, the ICZN President officially formed a Committee on the issue of ‘typeless species’. The Committee was comprised of Commissioners Krell (Chair), Ballerio and Bouchard. The mandate of the Committee was “To consider an appropriate action from the International Commission on Zoological Nomenclature on the issue of new species-group taxa proposed after 1999 without an extant name-bearing type, including cases where this type is stated to either not having been collected or having been subsequently released or otherwise discharged or lost to the effect that no original name-bearing type has been (or is likely to be) placed in a relevant collection. In case a Declaration is recommended, at least one suggestion of the exact wording should be provided. In case an Opinion or opinion paper is recommended, a lead author should be suggested”.

Under Articles 78.3 and 80.1 of the Code, a Declaration (provisional amendment to the Code) was drafted by the Secretariat, and on 2 November 2016 Commissioners were asked to vote on whether the amendment to the Code resulting from the proposed Declaration 45 “is not a major change but merely clarifies a provision of the Code” (Article 78.3). Over two-thirds of the Commissioners voted in agreement that it was not a major change to the Code (21 FOR, 3 AGAINST and 3 did not vote). The Declaration is hereby approved and under Article 80.1 shall remain in force until ratified or rejected by the International Union of Biological Sciences (IUBS), the international body from which the Commission derives its functions and powers (Article 77 of the Code).

Declaration 44 was published in 2017, BZN 73 (2–4): 96–97 and can be seen here