What is an ‘extant’ type specimen? Problems arising from naming mammalian species‐group taxa without preserved types

Abstract

ABSTRACT1. The International Code of Zoological Nomenclature allows the naming of new species without a type specimen ever having been preserved. This practice causes problems and is undesirable because if related, cryptic, sibling species are encountered later, it may not be possible either to allocate them with certainty to the earlier named species, or to determine them to be something different. 2.We hypothesised that examination of the instances in which mammalian species were named without preserved types would reveal certain problems that are not unique to them, but are encountered more frequently than when types are preserved. We also thought the Code's stipulation that preserved types are not required in the case of specimens that are no longer 'extant' would present special problems hitherto unremarked upon in the literature. 3. We conducted a review of cases involving putative new species of mammal named since 1900. These were analysed to see what special problems they present and the frequency of such problems. 4. We found that the Code's waiver of the requirement that a type specimen be deposited in a collection if the specimen is no longer extant presents numerous problems-in particular, that a living-at-large type specimen can still be 'extant' even if its whereabouts are unknown at certain times and/or it may no longer be alive. Illustrations alone being used to designate type specimens is especially problematic, owing to mammals' lack of meristic and other obvious distinguishing external characters. Hoaxes, the difficulty in determining that they are hoaxes, and various errors of taxonomic allocation appear to be especially common with names without preserved types. The Code should be revised to require preserved specimens as types for new names. Tissue samples alone for DNA analysis are not ideal for serving this purpose, but should be allowed to meet the requirement.

No longer based on photographs alone: refuting the validity of golden-crowned langur Presbytis johnaspinalli Nardelli 2015 (Mammalia, Primates, Cercopithecidae)

“…For the golden-crowned langur and three other species, their conclusion was 'unresolved'. A similar conclusion was drawn by Pine and Gutiérrez (2018): "It is currently unresolved whether the name is based on artificially modified animals or individuals of a new or already known species and to what genus the animals belonged." Rossi et al (2018) briefly discussed the description of Presbytis johnaspinalli and the partially artificial bleaching, but did not draw a conclusion on their status, noting that the issue deserves further enquiries.…”

“…In discussing the description and the validity of golden-crowned langur, attention was invariably drawn to the fact that it was based on photographs taken at an animal market by people other than the author of the species and that they were subsequently posted on the Internet, as well as whether or not the langurs in the photographs were indeed bleached or dyed (Butler 2015;Krell et al 2017;Pine and Gutiérrez 2018;Rossi et al 2018). More than once, parallels were drawn to the case of the yellow-necked parrotlet Forpus flavicollis Bertagnolio & Racheli 2010; this species was also described on the basis of a photograph of animals in trade (when the birds were in a rescue centre in Colombia, Bertagnolio and Racheli 2010).…”

A gene-tree test of the traditional taxonomy of American deer: the importance of voucher specimens, geographic data, and dense sampling

“…Clearly, substantial species-level taxonomic work is yet to be done. As the scientific community advances tackling the many taxonomic issues of cervid species, researchers should keep in mind that, despite the conservation status of some of these deer and the implicit difficulty to obtaining collecting permits for research, especially in the Neotropics, new species and subspecies should only be described when preserved museum specimens are available to document new names (see Ceríaco et al 2016 , Gutiérrez and Pine 2017 , Dubois 2017 and references therein, Pine and Gutiérrez [in press] ; contra Donegan 2008 , Marshall and Evenhuis 2015 ). In addition, and also to avoid obstructing scientific progress, upcoming studies should provide sufficient information regarding voucher specimen availability and detailed information regarding the provenance of samples from which they have obtained data; unfortunately, this is not customary.…”

基于遗传单系与鉴别特征的系统发生种的划分及其对哺乳动物分类学的意义

“…Examples of these plausible problems are abundant in the proposed classification of ungulates by Groves & Grubb ( 2011 ) (see below), but are by no means exclusive to it (e.g., Díaz et al, 1999 , 2002 ; Fonseca & Pinto, 2004 ; Solari, 2004 ; van Roosmalen et al, 2000 , 2007 ); numerous examples exist in early contributions to mammalian taxonomy (e.g., Miller, 1912 ; Pocock, 1941 ; Robinson & Lyon, 1901 ), and even the last decade has seen claims advocating for the recognition of a species made on the basis of phenotypic diagnoses of as few as one or two specimens—e.g., Meijaard et al, 2017 p. 513; see also Mantilla-Meluk ( 2013 ) for a monkey subspecies named on the basis of morphometric data and pelage coloration from only four specimens. Unfortunately, in some cases descriptions of species have been carried out not only with unacceptably small sample sizes but also merely based on images (illustrations, photos, or both) and lacking preserved type specimens (see Pine & Gutiérrez, 2018 for a review of cases and problems associated to this phenomenon). Although no data exist to support the notion that the collection of a single individual (for it to properly serve as a preserved holotype) significantly increases the probability of an already endangered species to become extinct, some researchers may prefer not to carry out such collection (e.g., Donegan, 2008 ; but see Dubois & Nemésio, 2007 ; Dubois, 2009 ), or it may be unfeasible due to impediments in obtaining collection permits.…”