A comment on Leal et al .: ‘Geometric morphometrics reveal that Conus anabathrum Crosse, 1865 (Neogastropoda:Conidae) should be an accepted species’

This paper examines the shifts in taxonomy and roles that the International Commission on Zoological Nomenclature (ICZN) have played in the debate of Gradiconus anabathrum being synonymized with either Gradiconus floridanus or Gradiconus scalaris. Gradiconus anabathrum (Crosse, 1865) has been an enigma for taxonomists for over 100 years primarily due to the failure of Crosse to designate a type locality, and the location of a population of organisms that is congruent. Notwithstanding, the holotype of C. anabathrum is clearly identifiable from the collection of Hugh Cuming held at the Natural History Museum, London, UK. Nevertheless, in spite of Gradiconus anabathrum being considered a lost species by Tomlin (1937) and Wagner & Abbott (1964), in 1980 Coomans declared that Gradiconus anabathrum was synonymous with Gradiconus floridanus (Gabb, 1869) (Coomans, Moolenbeek & Wils 1980). Notwithstanding this clarification, Gradiconus anabathrum and Gradiconus floridanus remain taxonomically confused within the literature, the names having been applied interchangeably by some authors. Leal et al. (2024)was incorrect to amalgamate Gradiconus floridanus (Gabb, 1869) and Gradiconus anabathrum based on an assumption which was not stated. Recent principle component analysis, which used the holotype of Gradiconus anabathrum, demonstrated that that species falls outside the distributional size variability of Gradiconus floridanus (Gabb, 1869) and similarly also outside the bounds of Gradiconus scalaris (Valenciennes, 1832), supporting the distinctiveness of Gradiconus anabathrum from both those species (Leal et al., 2024). We also note that Leal et al. failed to use the holotype of Gradiconus floridanus which is in the Academy of Natural Sciences of Drexel University, Philadelphia, USA and illustrated in Berschauer (2022), making the comparative analytical results in Leal et al. quite contrived to support a pre-existing assumption on their conception of validity of Gradiconus taxonomy. Gradiconus floridanus is an endemic cone species found only in the Suwannean Subprovince of the Carolinian Molluscan Province (Petuch & Berschauer, 2022, 2024). In contrast, recent studies comparing the morphology of Gradiconus anabathrum with other species in the genus Gradiconus determined it to be a junior synonym of Gradiconus scalaris (Berschauer, 2022), this is now considered an error; furthermore, the type locality for Gradiconus anabathrum was designated as off the west coast of Panama in the Eastern Pacific Molluscan Province (Berschauer, 2022). This paper examines the erroneous and problematic systematic entanglement of C. floridanus, Gradiconus scalaris and Gradiconus anabathrum and reaffirms their distinctiveness from each other; Gradiconus anabathrum is not a synonym of Gradiconus scalaris, and both differ from C. floridanus and any other American Gradiconus species. Early workers Tomlin (1937) and Wagner & Abbott (1964) considered C. anabathrum to be a variety of Conus japonicus Hwass in Bruguiẻre, 1792. However, Conus japonicus is now associated with Endemoconus spirofilis (Habe & Kosuge, 1970) which is found in the Japonic and Indo-Malaysian Provinces from southern Japan to the Philippines, and outside the collecting range for the Cuming expeditions. Coomans, Moolenbeek & Wils (1980) reframed the debate on C. anabathrum from the Pacific Ocean, declaring it was synonymous with C. floridanusGabb, 1869. Coomans, Moolenbeek & Wils (1980) designated the type locality of C. anabathrum to be “the coast of Florida” without any analysis or discussion whatsoever, other than merely stating in their remarks section that 'without a doubt the yellow-coloured shell of C. anabathrum is conspecific with C. floridanus from Florida and the Bahamas'. No conchological or morphological analysis was mentioned by the authors. This is taxonomy by decree and should be avoided as errors made in such pronouncements have potential legal and intellectual property implications (Maxwell & Underdown, 2022; Maxwell, 2023). Unfortunately, some subsequent authors have followed and cited Coomans, Moolenbeek & Wils (1980), without questioning, discussing or analysing the morphology or biogeography of the two taxa in question (Vink, 1985, 1987; Tucker, 2010; Tucker & Tenorio, 2009, 2013; Monnier et al., 2018). Further, notwithstanding Coomans’ synonymy by decree, the name of the well-known west Florida species Gradiconus floridanus was well accepted in the literature for over 100 years, even after Coomans, Moolenbeek & Wils (1980), and the ICNZ promotes stability in biological nomenclature (Tryon, 1881; Clench, 1942; , 1842, 1974; Perry & Schwengel, 1955; Wagner & Abbott, 1964; Romashko, 1974; Emerson & Jacobson, 1976; Dance, 1976; Walls, 1979; Rehder, 1981; Eisenberg, 1981; Abbott & Dance, 1983; Turgeon et al., 1988; Petuch & Berschauer, 2022, 2024). The lack of understanding of the difference between Gradiconus floridanus and Gradiconus anabathrum has led to historical activity seeking to have ICZN rulings on synonymy and precedence, which given our current understanding would now be redundant. At the time of the Coomans, Moolenbeek & Wils (1980) manuscript, Gradiconus floridanus was a well-known species from the west coast of Florida, USA. Recognizing that this synonymy would disrupt nomenclature in the literature Coomans, Moolenbeek & Wils (1980: 34) indicated that: “For the stability of nomenclature it is, however, not to be recommended to change the well-known and established name of Conus floridanus into C. anabathrum, although the latter has four years priority. We consider C. anabathrum a senior synonym of C. floridanus. The status of nomen oblitum would be advisable for C. anabathrum.” The International Code of Zoological Nomenclature contains rules governing the naming of taxa and sets forth “the principle of priority” in Article 23.1: “The valid name of a taxon is the oldest available name applied to it, unless that name has been invalidated or another name is given precedence by any provision of the Code or by any ruling of the Commission. For this reason, priority applies to the validity of synonyms [Art.23.3], to the relative precedence of homonyms [Arts. 53-60], the correctness or otherwise of spellings [Arts. 24, 32], and to the validity of nomenclatural acts (such as acts taken under the Principle of the First Reviser [Art. 24.2] and the fixation of name-bearing types [Arts. 68, 69, 74.1.3, 74.5]).” Ultimately, Walter Cernohorsky (1987) filed a petition with the International Commission on Zoological Nomenclature to suppress G. anabathtrum in favor of Gradiconus floridanus (ICZN case 2563) and following the filing of an opposing comment by Harasewych and Petit (1988) the Commission issued a split decision denying the petition to suppress the name Gradiconus anabathtrum in favour of Gradiconus floridanus (ICZN, 1989). It is important to note that this ICZN opinion was based purely upon the legal grounds of the rule of priority, and no inquiry was made into whether, in fact, the synonymy was based on well-reasoned analysis in the first place, which it has been demonstrated was in error (Berschauer, 2022). The 'principle of priority' as set forth in the ICZN Code is a modern incarnation of the 'law of priority' first codified by the British Science Association in 1842, known as the Strickland Code of Zoological Nomenclature. The law of priority as set forth in the Strickland Code (1842): 'The name originally given by the founder of a group or the describer of a species should be permanently retained, to the exclusion of all subsequent synonyms'. The stated purpose of the law of priority was to be a guiding principle to preserve the stability of biological nomenclature. Without a ruling by the ICZN to suppress the older name, Gradiconus anabathrum was required to be recognized as the proper name for the collective organisms that were Gradiconus floridanus and Gradiconus anabathrum (ICZN, 1999: Article 23.1). However, an ICZN ruling is not necessary, given Gradiconus anabathrum is not the same organism as the Suwannean Province endemic species Gradiconus scalaris based upon both traditional morphology and principal component analyses (Berschauer, 2022; Leal et al., 2024). One of the current hypotheses is that the holotype of Gradiconus anabathrum is in fact a beach worn juvenile specimen of Gradiconus scalaris which we now reject, based upon recent principal component analysis (Leal et al., 2024). The Leal et al. study reveals that the holotype of G. anabathrum is not within the confidence boundaries for either Gradiconus floridanus or Gradiconus scalaris. Therefore, until further evidence emerges to support synonymizing these two taxa, G. anabathrum should be considered a valid species, distinct and separate from Gradiconus floridanus. The authors thank Edward J. Petuch for his encouragement, and for imparting some of his knowledge and understanding of the principles of taxonomy and the intricacies of the code produced by the ICZN. There is no funding to be declared. There are no conflicts of interest pertaining to this paper.