Freshly pressed: a paper by Mike Rutherford describing a new species from Trinidad. “Radiodiscus hollidayi, a new species of Charopidae, is described from the island of Trinidad, Trinidad and Tobago. The description is based on conchological features alone: a tiny discoid shell with a distinct protoconch with 6–8 cordlets, fine ribs on the teleoconch, and a deep umbilicus. The snail is found in leaf litter and humus in a variety of forest habitats across Trinidad. A table compares a common set of measurements and characters across 27 other species of Radiodiscus“.
A nice addition to the fauna of Trinidad, which still deserves an updated checklist on which the author is working.
Rutherford, M.G., 2020. A new species of Radiodiscus (Gastropoda: Eupulmonata: Charopidae) from Trinidad and Tobago. – Archiv für Molluskenkunde 149(1): 67-74.
Recently published by Freitas et al., a survey at this archipelago. “Oceanic island biotas are known by their high levels of endemism and high vulnerability. In Brazil, only few islands have been studied. The present study reports general information on the distribution and abundance of terrestrial gastropods of the Fernando de Noronha archipelago, a group of islands 345 km off the Brazilian coast. In total, four species of land snails were recorded: the endemics Hyperaulax ridleyi (Smith, 1890) and Ridleya quinquelirata (Smith, 1890), and the widely distributed Beckianum beckianum (Pfeiffer, 1846), and Allopeas gracile (Hutton, 1834). The most abundant species was H. ridleyi. By reporting the present situation of native land snails of Fernando de Noronha, this study provides data that could help in their conservation, comprising an important first step for planning future conservation strategies for the land biota of the whole archipelago“.
Freitas, A.V.L. et al., 2019. Land snails of the Fernando de Noronha archipelago, Brazil. – American Malacological Bulletin, 37(2): 66-69.
Araya & Miquel recently published a paper in which they introduced a new micromollusc: “Stephacharopa paposensis n.sp. is described from shells collected in coastal areas of Paposo, Región de Antofagasta, northern Chile, associated with native bromeliads and cacti living among rocks and coarse sand. This is the second species of Stephacharopa found in northern chile and one of the northernmost species of Charopidae found in this country”.
Micromolluscs have been largely overlooked so far in the Neotropical fauna, and much more novelties are to be expected when malacologists focus on these groups during collecting in the various countries.
Araya, J.F. & Miquel, S.E., 2018. A new Stephacharopa (Gastropoda: Punctoidea: Charopidae) from Paposo, northern Chile. – Journal of Conchology, 43 (2): 129-132.
Based on a small collection already made in 1982, Araya et al. have just published a paper on the snail fauna near Antofagasta.
“New records for Bostryx holostoma (Pfeiffer, 1846), Pupoides minimus (Philippi, 1860), Stephacharopa calderaensis Miquel & Araya, 2013 and an unidentified charopid species are presented on the basis of specimens collected near the city of Antofagasta, in northern Chile. This is the first record for S. calderaensis after its description, extending its known distribution about 350 km northwards. Details on the protoconch of B. holostoma are presented for the first time, and this species extends its distributional range 145 km southwards. The microhabitat of these species in litho-refugia may explain the presence of these minute terrestrial mollusks in hyper arid northern Chile, further highlighting the need of additional studies of this neglected fauna”.
Especially the protoconch structure of Bostryx holostoma is interesting, as this reveals a spiral structure which is not present in other Chilean Bostryx species. As unpublished DNA results of species from this genus from different countries reveal, this genus may well be polyphyletic.
Araya, J.F. et al., 2017. New records of terrestrial mollusks (Gastropoda: Stylommatophora) from Antofagasta, northern Chile. – Revista Mexicana de Biodiversidad, 88: 769-772.
Cave systems are always an interesting place for biologists to see what animals live there and might have adapted themselves to a subterranean life. According to Silva & Ferreira (2016) “[t]he term hotspots of subterranean biodiversity has been used to define subterranean habitats with an arbitrary cutof of twenty or more obligate stygobitic and troglobitic species. Until present, no hotspots of subterranean biodiversity had been identified in South America. Thus, the objective of this work is to present the first two hotspots of subterranean biodiversity in that continent. The two hotspots of subterranean biodiversity are the Toca do Gonçalo cave (22 spp.) and Areias cave systems (28 spp.). The cave species, some of them considered relict species, belong to the Platyhelminthes (1 sp.), Nemertea (1 sp.), Gastropoda (2 spp.), Amphipoda (2) Isopoda (7), Decapoda (1), Collembola (5), Coleoptera (5), Ensifera (1), Sternorrhyncha (1), Zygentoma (1), Diplopoda (6) Chilopoda (5) Araneae (2), Opiliones (1) Palpi- gradi (2), Pseudoscorpiones (4), and Osteicthyes (2). Although both caves, together, have 50 troglobitic species, only 38% of these species are formally described. Both caves have perennial water bodies, but terrestrial obligate cave invertebrates are dominant in number of species in both systems (around 77%). While the Areias system is partially contained in a conservation unit, Toca do Gonçalo cave is currently unprotected, although it certainly deserves protection”.
One terrestrial species was found, Rotadiscus sp. Other recent reports on snails from caves may be found here and here.
Silva, M.S. & Ferreira, R.L., 2016. The first two hotspots of subterranean biodiversity in South America. – Subterranean Biology, 19:1-21.
The abstract of the new paper by Araya (2016) reads: “Among the terrestrial invertebrates, the molluscan species of central and northern Chile have been scarcely studied and here, for the first time, a record of the diversity of land snail species of Los Molles (32◦14′ S, 71◦31′ W), in the Valparaíso region, central Chile is reported. Four species were found: Chiliborus rosaceus (King & Broderip, 1831); Lilloiconcha lopezi Araya & Aliaga, 2015; Plectostylus chilensis (Lesson, 1830), and Plectostylus reflexus (Pfeiffer, 1842); all of them are ground dwelling snails, endemic, occurring in small geographical ranges or in fragmented populations along northern and central Chile; L. lopezi is an endemic species to Los Molles. The geographic distribution records of P. chilensis and P. reflexus are also extended and illustrations of the species and distribution records are presented. The areas around Los Molles harbor a comparatively high diversity of plants and invertebrates, and they should be considered in future conservation efforts”.
Araya, J.F., 2016. On some land snails (Mollusca: Gastropoda) of Los Molles, central Chile. – Revista Mexicana de Biodiversidad, 87:1365–1368.
Miquel & Rodriguez (2015 ) published a new paper on fossil shells from Miocene deposits in Patagonia, Argentina. Among them four new species, of which one is placed in a new genus.
“A remarkable fossil assemblage composed of five gastropod taxa is described from the Early Miocene of Santa Cruz (Patagonia, Argentina) in southernmost South America. The assemblage includes extinct and living genera South America, and on geographic distributions and represent background new information on spatial and across time distributions as well as identification of new taxa. A new taxon, Patagocharopa enigmatica n. gen. n. sp., is tentatively assigned to Charopidae. Gastrocopta patagonica n. sp. (Vertiginidae) represents the oldest record of Gastrocopta in Argentina and the southernmost record for the Americas. Punctum patagonicum n. sp. (Punctidae) represents the first record of Punctum for continental South America, and characterized by a protoconch with traces of axial costulae and a teleoconch with strong radial ribs. Zilchogyra miocenica n. sp. is the first Miocene record of the charopid genus Zilchogyra. Fragments of a possible Scolodonta (Scolodontidae) are recorded. Overall, the assemblage represents an important and useful paleoenvironmental tool. This fauna suggests that a more temperate and humid environment than today—with a more dense vegetation cover—was prevalent at this site during the Early Miocene”.
Although the paper appeared in the September 2015 issue of the Journal of Paleontology, the actual publication date seems 2016. In the PDF I received it says “Published online: 22 March 2016”, while also the copyright is from this year. As new taxa are introduced in this paper, this is relevant information.
Miquel, S.E. & Rodriguez, P.E., 2015 . A novel late Early Miocene assemblage of terrestrial gastropods from Santa Cruz (Patagonia, Argentina). – Journal of Paleontology, 89(5): 748-761.
Papers on Neotropical fossils are rare, but Sergio Miquel is a regular contributor of them. Although Turazzini & Miquel (2014) was overlooked by me, I mention the paper now it came to my attention. The abstract follows after the break.
“Numerous fossil gastropods have been recorded in an edaphic level of the middle section of the the Aisol Formation (Mendoza Province, Argentina). This stratigraphic section bears an association of fossil mammals suggesting an early Pliocene age (possible Montehermosan SALMA). Up to four taxa of gastropods have been identified, belonging in Succinea Draparnaud (Succineidae), Gastrocopta Wollaston (Vertiginidae), Bostryx Troschel (Bulimulidae), and a new species of Radiodiscus Pilsbry and Ferriss (Charopidae). The fossil record of terrestrial pulmonate mollusks in Argentina is scarce and mainly restricted to the Quaternary. Thus, the record of these taxa is of paramount importance because it constitutes the oldest record of Gastrocopta and Succinea in Argentina, the first record of Bostryx in Mendoza Province, and the first record of the family Charopidae (Radiodiscus sanrafaelensis nov. sp.) in Pliocene deposits of Argentina”.
Turazzini, G.F. & Miquel, S.E., 2014. A terrestrial gastropod community from the Early Pliocene (Neogene) of Mendoza, Argentina, with description of a new species of Radiodiscus Pilsbry and Ferriss, 1906 (Mollusca: Pulmonata: Charopidae). – Ameghiniana, 51(5): 396-404.
Luiz Simone has posted several recent papers, and one of them has not yet been mentioned in this blog: Cunha et al. (2015) reported on the terrestrial microsnails collected by the Marion Dufresne Expedition in 1987 at Trindade Island, Brazil.
No new species are described in this paper, but it is good to have this report on the often overlooked part of the malacofauna, especially from this oceanic island.
Cunha, C.M., Salvador, R.B. & Simone, L.R.L., 2015. The terrestrial microgastropods of Trindade Island, Brazil. – Spixiana 38: 139–143.
Miquel & Rodriguez (2016) describe a fossil fauna found in southern Patagania with an interesting composition. One new genus and four new species are described.
The abstract is: “A remarkable fossil assemblage composed of five gastropod taxa is described from the Early Miocene of Santa Cruz (Patagonia, Argentina) in southernmost South America. The assemblage includes extinct and living genera South America, and on geographic distributions and represent background new information on spatial and across time distributions as well as identification of new taxa. A new taxon, Patagocharopa enigmatica n. gen. n. sp., is tentatively assigned to Charopidae. Gastrocopta patagonica n. sp. (Vertiginidae) represents the oldest record of Gastrocopta in Argentina and the southernmost record for the Americas. Punctum patagonicum n. sp. (Punctidae) represents the first record of Punctum for continental South America, and characterized by a protoconch with traces of axial costulae and a teleoconch with strong radial ribs. Zilchogyra miocenica n. sp. is the first Miocene record of the charopid genus Zilchogyra. Fragments of a possible Scolodonta (Scolodontidae) are recorded. Overall, the assemblage represents an important and useful paleoenvironmental tool. This fauna suggests that a more temperate and humid environment than today—with a more dense vegetation cover—was prevalent at this site during the Early Miocene”.
Miquel, S.E. & Rodriguez, P.E., 2016. A novel late Early Miocene assemblage of terrestrial gastropods from Santa Cruz (Patagonia, Argentina). — Journal of Paleontology X: 1–14 (advance access).