Monthly Archives: February 2017

Brazilian cave snails

Another freshly pressed paper is by Salvador et al. on Brazilian cave snails. The abstract reads “A sample of land and freshwater snails, mainly pulmonates, was recently collected in caves in Goiás and Bahia states, Brazil. Twenty-one species were found in the material. The following species are reported for the first time for Goiás state: Cecilioides consobrina (Ferussaciidae), Dysopeas muibum and Stenogyra octogyra (Subulinidae), Entodina jekylli and Prohappia besckei (Scolodontidae; also reported for the first time for Bahia state), Pupisoma dioscoricola (Valloniidae). A new species from Goiás is described here-in: Gastrocopta sharae sp. n. (Gastrocoptidae). The new records and species addressed here constitute important findings, helping to fill distributional gaps and improving the knowledge of the local molluscan fauna, an essential step for future conservation efforts”.

schermafbeelding-2017-02-19-om-06-18-59

Besides the species newly reported for the two states, there are also additional records of the following land snails: Helicina angulata Sowerby, 1873 (Helicinidae), Cyclodonta sexdentata (Spix in Wagner, 1827) and Ringicella luetzelburgi Weber, 1925 (Odontotomidae), Happia glaberrima Thiele, 1927 (Scolodontidae), Allopeas micra (d’Orbigny, 1835) and Leptinaria concentrica (Reeve, 1849) (Subulinidae); five species are identified only to genus level.

This study complements earlier studies on the cave malacofauna in Brazil from part of the authors (see here and here).

Reference:
Salvador, R.B., Cavallari, D.C. & Simone, L.R.L., 2017. Taxonomical study on a sample of land and freshwater snails from caves in central Brazil, with description of a new species. – Zoosystema and Evolution, 93 (1): 193-141.

Narrow-range Cerion from Cuba

Freshly pressed…. In the latest number of The Festivus that I found this morning in our library, González et al. have a paper on Cerion from Cuba. “The exceedingly polytypical genus Cerion (Röding, 1798), with around 91-92 species described for Cuba is still poorly studied. The urgent need of more studies related to ecology, genetics, environmental components, morphology, conservation status plus a serious taxonomic evaluation of the genus in the archipelago is more than evident. The present paper reviews the narrow-range Cerion taxa that occur in the coastal zone of the Holguin province, in northeastern Cuba, including comments on each taxa. Additional observations related to other taxa from the same geographic coastline area are included to reinforce the importance of further research studies that the authors believe need to be conducted”.

schermafbeelding-2017-02-16-om-13-14-52

The paper comprises data on 15 taxa (species or subspecies) with adequate (although somewhat darkish) photographs of each taxon, and two plates which facilitate comparisons.

Reference:
González, A., Fernández, A., Lajonchere, L.A. & Berschauer, D.P., 2017. Narrow-range taxa of Cerion (Mollusca: Cerionidae) in the northeastern province of Cuba. – The Festivus, 49 (1): 3–17.

Did Neotropical snails occur in Africa and Europe?

Fossils allow us a peek into the past, and although a lot remains uncertain and sometimes highly speculative (no molecules but only shell morphology to start with), they offer sometimes challenging views on worlds that have gone.

What we now call the Neotropics possibly once had a wider extension, and a team of Algerian and European scientists have made a study of Algerian shells that possibly give a clue. Hammouda et al. (2017) present a review of Eocene “Bulimes” and reached interesting but still tentative results.

schermafbeelding-2017-02-09-om-06-48-03

schermafbeelding-2017-02-09-om-06-46-57

Their abstract reads “Terrestrial gastropods occur in many North African localities in Eocene continental deposits. Here we analyse the faunal assemblage from the Hamada de Meridja Formation in southwestern Algeria, dated as Early to Middle Eocene on the basis of charophytes. The assemblage consists of three closely related species that to date have been classied either in the extant Madagascan genus Leucotaenius v. Martens, 1860, or in the SW European Eocene genera Romanella Jodot, 1957 and Vicentinia Jodot, 1957. This is rejected for shell morphological and phylogeographical reasons, and a new classication as Maghrebiola gen. nov. is proposed. Maghrebiola is tentatively placed in the South American family Strophocheilidae, as species from the Early Eocene Itaboraı Basin of Brazil, currently placed in the genus Eoborus Klappenbach and Olazarri, 1970 in the family Strophocheilidae, superfamily Acavoidea, have a very similar shell habitus. This record possibly extends the known geographical range of the Strophocheilidae into the African continent during the Eocene. Immigration of this stock into North Africa during the Cretaceous via a still existing plate connection is assumed. An attribution of Maghrebiola to the African family Achatinidae is unlikely for shell morphological reasons despite certain habitus similarities, although the Priabonian genera Arabicolaria and Pacaudiella from Oman most likely belong into this family, and not to the Vidaliellidae as originally proposed. Possible causes for the very low diversity of the assemblage are mainly unfavourable living conditions, i.e. a relatively dry climate resulting in sparse vegetation and only occasional presence of water bodies, which may have had increased salinities, accounting for the lack of freshwater mollusks. The absence of any competing large gastropods may possibly have facilitated high intraspecic variability leading to sympatric occurrence of three closely related species, due to the animals occupying a wide range of available ecological niches. As the species discussed here have also been attributed to the genera Romanella and Vicentinia in the Vidaliellidae, we provide an appendix with annotated characterisations of most genera of the Vidaliellidae and list the nominal species assigned to them. This family is tentatively placed in the South American superfamily Orthalicoidea; its stock would have similarly immigrated from South America, but have successfully colonized mainly SW Europe, with only one Eocene species [Romanella kantarensis (Jodot, 1936)] recognized in Algeria”.

schermafbeelding-2017-02-09-om-06-53-14

schermafbeelding-2017-02-09-om-06-52-35

The most recent, total overview of fossil and Recent Gastropoda was by Zilch, who classified the genera Romanella and Vidaliella with others in the “?Familia Anadromidae” within the Bulimulacea [currently Orthalicoidea] (Zilch, 1960); these genera are now placed in a family on their own, but based on their morphology there might be a resemblance with the Megaspiridae (e.g. Thaumastus). The link between the Mediterranean area and South America is further shown in the presence of the Clausiliid Neniinae, which the authors use as one of their arguments for their grouping of Maghrebiola with the Strophocheilidae. All this is an interesting but not implausible hypothesis.

References:
Hammouda, S.A., Kadolsky, D., Adaci, M., Mebrouk, F., Bensalah, M., Mahbouhi, M. & Tabuce, R., 2017. Taxonomic review of the “Bulimes”, terrestrial gastropods from the continental Eocene of the Hamada de Méridja (northwestern Sahara, Algeria) (Mollusca: Stylommatophora: Strophocheilidae?), with a discussion of the genera of the family Vidaliellidae. — Paläontologische Zeitschrift, (advance online) doi:10.1007/s12542-016-0333-5
Zilch, A., 1960. Gastropoda 2. Euthyneura. In: Schindewolf, O. (ed.) Handbuch der Paläozoologie, 6 (3–4): 401–834. Berlin: Borntraeger.

 

Review of part of Hispaniolan Annulariidae

The third post on Watters’ 2016 papers concerns his review of the Paracondria (Chondropomorus) complex. “Nineteen species are recognized including eight new species: Parachondria anatolensis n. sp., Parachondria arcisensis n. sp., Parachondria daedalus n. sp., Para- chondria heatheraikenae n. sp., Parachondria isabellinus n. sp., Parachondria muchai n. sp., Parachondria silvaticus n. sp., and Parachondria stigmosus n. sp. Distributional and habitat notes are given for additional taxa. Chondropoma marinum “Weinland” Reeve, 1863, is regarded as a nomen dubium. Chondropoma (Chondropomorus) moroni Bartsch, 1946, is reidentified as Crossepoma emilianum (Weinland, 1862). Chondropoma simplex Pfeiffer, 1852, regarded by Bartsch (1946) as a Chondropomorus, is considered a Chondropoma”.

schermafbeelding-2017-02-08-om-08-29-34 schermafbeelding-2017-02-08-om-08-30-03

Reference:
Watters, G.J., 2016. Review of the Hispaniolan Parachondria (Chondropomorus) complex (Gastropoda: Littorinoidea: Annulariidae). – Zootaxa, 4127 (2): 245–275.

New Annulariidae from Hispaniola

Today two papers by Thomas Watters describing new species from the island of Hispaniola. Watters’ (2016a) abstract is “Chondropoma bellavittatum new species is described for the Haitian species referred to by Bartsch, 1946, as Chondropoma semilabre Lamarck, 1822. This latter species is shown to be a different taxon from the Bahamas”.

schermafbeelding-2017-02-08-om-08-03-58

The second paper, which appeared in the same journal, deals with a new species from the eastern part of the island. “Parachondria joyeuse is described from the eastern Dominican Republic. The new species is characterized by a thin, high- spired, nearly smooth shell and a peculiar color pattern. It is placed in Parachondria with reservation”.

schermafbeelding-2017-02-08-om-08-10-26

References:
Watters, G.T., 2016a. Identification and redescription of the Haitian Chondropoma semilabre of Bartsch, 1946, non Lamarck, 1822 (Gastropoda: Annulariidae). – The Nautilus, 130 (1): 23–25.
Watters, G.J., 2016b. Parachondria joyeuse: a peculiar new species of Hispaniolan Annulariidae (Gastropoda: Littorinoidea). – The Nautilus, 130 (4): 164–165.

New Annulariidae from Dominican Republic

Thomas Watters has published last year a series of papers on Antillean Annulariidae which have not been mentioned here. Today I start with a paper on the Dominican Republic; the abstract reads “A new genus and species of Annulariidae are described from the Dominican Republic: Tessaripoma n. gen. and Tessaripoma arenarium n. sp. The genus also contains T. hooksi (Watters & Duffy, 2010) and T. alyshae (Watters & Duffy, 2010). The genus is endemic to the eastern end of the Hoya de Enriquillo between the Tiburon/Barahona Peninsula and the remainder of Hispaniola”.

schermafbeelding-2017-02-08-om-07-22-31 schermafbeelding-2017-02-08-om-07-23-06

Reference:
Waters, G.T., 2016. A new genus and species of Annulariidae (Gastropoda) from the Dominican Republic: Tessaripoma n. gen. and Tessaripoma arenarium n. sp. –  Novapex, 17 (2-3): 51–54.

Molluscs from Isla de la Juventud, Cuba

A checklist was published of land snails from the Sierra Bibijagua on the Isla de la Juventud, south of Cuba by Herrera-Uria (2016). The abstract reads “Sierra Bibijagua are marmoreal elevations located on northern Isla de la Juventud (Island of Youth), southwestern Cuba. Isla de la Juventud is the largest island (2,200 km2) of the Canarreos Archipelago, Greater Antilles. A checklist of terrestrial molluscs re- corded from Sierra Bibijagua is presented, including the following information: synonymy, type locality, updat- ed distribution, endemism, and photographs of shells and living individuals whenever possible. e checklist comprises 12 families and 16 genera currently known from the area, including six new records: Farcimen pro- cer, Leidyula oridana, Liguus fasciatus, Subulina octona, Glandinella poeyana, and Bradybaena similaris”.

schermafbeelding-2017-02-07-om-15-26-06

The paper can be found here.