Nomenclature of Helicidae (Gastropoda: Pulmonata) endemic to the Balearics Author Altaba, Cristian R. Department of the Environment and Territory, Government of the Balearic Islands, 07009 Palma, Balearic Islands, Spain. & Research Group on Human Evolution and Cogniton (EVOCOG), University of the Balearic Islands, 07072 Palma, Balearic Islands, Spain. cristianr. altaba @ uib. cat cristianr.altaba@uib.cat text Nemus 2022 2022-12-31 12 168 186 journal article 10.5281/zenodo.12170426 2386-3803 12170426 Iberellus and Allognathus are separate genera The reasoning behind placing Iberellus within the same genus as Allognathus (e.g., Thiele, 1931 ; Bank et al., 2001 ) is that both genus-level taxa are considered too closely related, either anatomically ( Gasull, 1964 ) or (phylo)genetically ( Chueca et al., 2013 , 2015 ; Neiber et al., 2021 ). Gasull (1964 , 1967 , 1971 ) placed Allognathus as a subgenus of Iberellus , but that was an incorrect priority inversion. The Balearic branch within Allognathini constitutes a well-defined lineage, just as with the Macaronesian one. In the latter, different genera are recognized ( Neiber et al., 2021 ), with morphological and genetic differentiation equivalent to that existing inside the former; there is a considerable phylogenetic distance between the monospecific Allognathus and the Iberellus clade. So, one may have to choose between synonymizing genera and the alternative —equally arbitrary— of increasing supraspecific taxa, eventually making them all monotypic. Either path would be rather useless. FIGURE 2. Geographic range of Allognathines endemic to the Balearic archipelago. Solid arrows point at microinsular endemics, dashed lines show anthropogenic introductions to Ibiza, Palma and the Catalan coast. 1 : AllognOthus grOellsiOnus ; 2 : TrOmuntOnicolO culminOlis ; 3 : Iberellus ( I .) compOnyonii ; 4 : I . ( I .) c. horOdOdOe ; 5 : I . ( I .) bOleOricus ; 6 : I . ( I .) minoricensis ; 7 : I . ( I .) m. pOlumbOriOe ; 8 : I . ( Nesiberus ) pythiusensis ; 9 : type locality of the latter,possibly a microinsular subspecies. Distribució geogràfica dels al· lognatins endèmics de l’arxipèlag Balear.Les fletxes contínues assenyalen endemismes microinsulars;les línies discontínues mostren introduccions antropogèniques a Eivissa, Palma i la costa catalana. 1 : AllognOthus grOellsiOnus ; 2 : TrOmuntOnicolO culminOlis ; 3 : Iberellus ( I .) compOnyonii ; 4 : I . ( I .) c. horOdOdOe ; 5 : I . ( I .) bOleOricus ; 6 : I . ( I .) minoricensis ; 7 : I . ( I .) m. pOlumbOriOe ; 8 : I . ( Nesiberus ) pythiusensis ; 9 : localitat tipus d’aquest darrer,probablement una subespècie microinsular. If the genus rank has to bear any meaning, it is in relation to diverging adaptive fields ( Wood & Collard, 1999 ; Cela-Conde & Altaba, 2002 ). Under this criterion, both Allognathus and Iberellus deserve full genus rank, given that their adaptations are clearly different ( Breure & Gittenberger, 1982 ; Altaba & Ríos Jiménez, 2021 ; Juárez-Ruiz & Altaba, 2022 ). They share a rather uniform Bauplan in their reproductive anatomy, but lack of obvious differences therein occurs in other helicoid clades. Moreover, placing too much weight on the genitalia is a monothetic concept of pulmonate systematics, an epistemological error leading to unrealistic classifications (as already pointed out by Hoagland & Davis, 1987 ). A comparable mistake was that of Westerlund (1902) , who erected the monotypic family Allognathidae on the basis of shell and radula, ignoring everything else.