ISSN 2755-3531
Marijn T. Roosen, Rodrigo B. Salvador & Abraham S. H. Breure
Abstract. The revision of the genera of Scolodontidae by our team continues, reaching its fourth instalment. In this paper, the species traditionally included in Miradiscops H.B. Baker, 1925 are discussed. Miradiscops is retained for all species with a pitted protoconch and pitted teleoconch sculpture and discoid shells with a wide umbilicus. Species with a striate teleoconch sculpture, smooth protoconch, and more lenticular shell with a narrower umbilicus are classified in Mayadiscops gen. nov. The type material of all species allocated to these two genera are figured here to assist future studies. Some species formerly assigned to Miradiscops are here reclassified into other Scolodontidae genera. The following new combinations are made: Scolodonta andivaga Pilsbry, 1932; Mayadiscops balboa (Pilsbry, 1930) comb. nov.; Tamayoa (Tamayops) bladenensis (D.S. Dourson, Caldwell & J.A. Dourson, 2018) comb. nov.; Scolodonta florezi (Weyrauch, 1967) comb. nov.; Mayadiscops hovestadti (van Leeuwen & Salvador, 2024) comb. nov.; Tamayoa (Tamayops) implicans (Guppy, 1868) comb. nov.; Mayadiscops maya (Pilsbry, 1920) comb. nov.; Mayadiscops opal (Pilsbry, 1920) comb. nov.; Mayadiscops ridiculus (Pilsbry, 1930) comb. nov. Finally, Miradiscops striatae D.S. Dourson, Caldwell & J.A. Dourson, 2018 is considered a junior synonym of Mayadiscops maya comb. nov.
Key words. Land snails, neotropics, new genus, Scolodontoidea, Stylommatophora, type specimens
Publication date. 17 July 2025
DOI. https://doi.org/10.61733/jconch/4552
Juan Francisco Araya, Cecilia Osorio, Valentina Olave, Juan Antonio Aliaga
Abstract. Petricola ramirezi Araya & Osorio, 2019, a shallow-water nestling petricolid bivalve, was originally described from specimens collected washed ashore at El Tabo, central Chile (33°27′S, 071°38′W). This species is unique from all other bivalve species in the area in nestling inside empty shells of the barnacle Balanus laevis. In this study, we present new geographic records for this species based on specimens collected at several localities in northern and central Chile. These results extend the geographical distribution of P. ramirezi by approximately 1,089 km from its only previously known locality at El Tabo northwards to Caldera (27°04′S, 070°49′W) and southwards to Lirquén (36°42′S, 072°58′W). Additionally, we present the first fossil record for P. ramirezi based on specimens collected nestling inside empty shells of B. laevis from a Pleistocene site in the El Morro area, Caldera, northern Chile. These results confirm the presence of this species along an expanded geographical distribution on the present-day Chilean coasts and reveal that P. ramirezi has been present in the northern part of the country since at least the Pleistocene. The particular and specialized lifestyle of this species, nestling inside empty barnacle shells, suggests that this strategy—providing protection from predators and from sudden environmental changes—may have contributed to the survival of this species in the area since the Pleistocene.
Key words. Range extension, barnacles, ecological niche, Chile, southeastern Pacific Ocean
Publication date. 18 August 2025
DOI. https://doi.org/10.61733/jconch/4553