Tag Archives: urocoptidae

Pinning down Tenuistemma

Under this (beginning of the) title, Uit de Weerd & Fernández has just made available a paper on the distribution and relationships of an Urocopitid species from eastern Cuba.

We report an extraordinary case of local and extreme shell-morphological differentiation within a group of otherwise relatively uniform eastern Cuban land snails. Analyses of multi-copy nuclear (ITS2) and of mitochondrial (COI) DNA sequences congruently place the ‘genus’ Tenuistemma, occurring monotypically on the Yunque de Baracoa mountain in eastern Cuba, within the more wide-spread species Pleurostemma perplicata from adjacent lower areas. This result is in sharp contrast with patterns of variation in supposedly diagnostic shell-morphological characters, namely (1) differences in both shell form and shell sculpture between Tenuistemma and P. perplicata, (2) the shell- morphological coherence of paraphyletic P. perplicata and (3) the resemblance between P. perplicata and phylogenetically and geographically more distant species placed in Pleurostemma. We conclude that Tenuistemma evolved from P. perplicata on the Yunque de Baracoa, a process that probably started between 0.01 and 1.42 million years ago. The remarkable set of shell features distinguishing Tenuistemma from P. perplicata probably evolved as a result of unique local selection pressures, possibly affecting multiple characters linked in shell development. This study provides a basis for further research into the evolutionary processes behind this remarkable morphological transition. To render the genus Pleurostemma monophyletic, we propose to transfer P. perplicata to the genus Tenuistemma”.

This research is interesting as it hypothesises on the local evolution of snails under different factors. As such there is a link to research on carinated species, of which a paper on Peruvian Bostryx is currently being prepared.

Reference:
Uit de Weerd, D.R. & Fernández V., A., 2017. Pinning down Tenuistemma (Pulmonata: Urocoptidae): local evolution of an extreme shell type. – Biological Journal of the Linnean Society, XX: 1-12. DOI: 10.1093/biolinnean/blx041

Two new Urocoptidae from Cuba

Herrera-Uria et al. (2016) described two new species from Isla de la Juventud, Cuba: Cochlodinella pinera and C. pirata. This is the first record of this genus for the island. Besides descriptions also photographs of living material is presented.

Reference:
Herrera-Uria, J, Espinosa, J. & Ortea, J., 2016. Dos nuevas especies del género Cochlodinella Pilsbry & Vanatta, 1898 (Mollusca: Gastropoda: Urocoptidae) de la Isla de la Juventud, Cuba. – Revista de la Academia Canaria de Ciencias, 28: 89-96.

New Cuban Urocoptids

In the annual journal of the Santo Domingo natural history museum, a paper appeared in which Herrera-Uria and Espinosa described two new Urocoptidae from Cuba.

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“Two new species of the genera Liocallonia Pilsbry, 1902 and Tetrentodon Pilsbry, 1903 are described. These species belong to the “Miguel L. Jaume” historical malacological collection housed in the National Museum of Natural History of Cuba. Photographs of the shells are presented”.

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One of the species is known only by the holotype, the second species is based on twelve specimens.

Reference:
Herrera-Uria, J. & Espinosa, J., 2016. Descripción de dos especies nuevas de Liocallonia y Tetrentodon (Gastropoda: Pulmonata: Urocoptidae) procedentes de la collección “Miguel L. Jaume” del Museo Nacional de Historia Natural de Cuba. – Novitates Caribaea, 10: 31-37.

Urocoptidae revisited

Uit de Weerd et al. (2016) have published a paper on the evolutionary history of biogeography of the land snail family Urocoptidae. It is a sequel following previous papers of Uit de Weerd dealing with the Caribbean region.

The authors reconstructed the phylogeny of Urocoptidae based on multi-locus (partial 28S, H3 and COI sequences) analyses (MrBayes, BEAST, GARLI) of 65 species, representing 44 recognized genera. Biogeographical analyses of a subset of the time-calibrated BEAST trees were made both with (DEC and DEC+J analysis in BioGeoBEARS) and without (S-DIVA in RASP) palaeo-geographical assumptions. In the DEC and DEC+J analyses we examined the effect of different settings for dispersal between directly connected areas relative to that between areas without direct land connection. Urocoptidae has been present on the Greater Antilles Arc from at least Middle Eocene onwards. Morphologically diverse and previously unrecognized clades evolved on most Caribbean (palaeo)islands. Jamaica was colonized at least twice. Dispersal multiplier matrices with moderately constrained dispersal between areas without direct land connections describe the phylogeographical history of the family with higher DEC and DEC+J lnL scores than uniform matrices. Urocoptids constitute an old element of the Greater Antillean biota, predating a proposed GAARlandia landspan connection to South America. The biogeographical history and evolution of Urocoptidae were shaped primarily by the geographical distribution of Caribbean landmasses, in combination with occasional oversea dispersal. Oversea dispersal allowed colonization of palaeogeographically isolated areas, such as Jamaica and present-day western Cuba, where presumably the absence of ecological competitors led to independent radiations into similar shell types. A follow-up paper will be dealing with the taxonomic consequences of this study.

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With the representation of 44 genera out of the total 65 recognized genera within the family, this is a comprehensive molecular analysis. No other Caribbean family has been treated this way, thus this study provides unique insights and helps to test competing biogeographical theories about land snail distribution in this region.

Reference:
Uit de Weerd, D.R., Robinson, D.G. & Rosenberg, G., 2016. Evolutionary and biogeographical history of the land snail family Urocoptidae (Gastropoda: Pulmonata) across the Caribbean region. – Journal of Biogeography (early online access) http://wileyonlinelibrary.com/journal/jbi | doi:10.1111/jbi.12692

Evolution and biogeography of Urocoptidae

Just published, the very interesting paper by Dennis Uit de Weerd et al. presents new data on the phylogenetics of the land snail family Urocoptidae. They also tested some biogeographical hypotheses using the phylogeny and present as results: “Urocoptidae has been present on the Greater Antilles Arc from at least Middle Eocene onwards. Morphologically diverse and previously unrecognized clades evolved on most Caribbean (palaeo)islands. Jamaica was colonized at least twice. Dispersal multiplier matrices with moderately constrained dispersal between areas without direct land connections describe the phylogeographical history of the family with higher DEC and DEC+J lnL scores than uniform matrices”.

UitdeWeerd2016

As their main conclusions they present: “Urocoptids constitute an old element of the Greater Antillean biota, predating a proposed GAARlandia landspan connection to South America. The biogeographical history and evolution of Urocoptidae were shaped primarily by the geographical distribution of Caribbean landmasses, in combination with occasional oversea dispersal. Oversea dispersal allowed colonization of palaeogeographically isolated areas, such as Jamaica and presentday western Cuba, where presumably the absence of ecological competitors led to independent radiations into similar shell types”. In a future paper a taxonomic revision of the family and of the genus Brachypodella will be published.

Reference:
Uit de Weerd, D., Robinson, D.G. & Rosenberg, G. (2016) Evolutionary and biogeographical history of the land snail family Urocoptidae (Gastropoda: Pulmonata) across the Caribbean region. – Journal of Biogeography [advanced access]: 1–15.

Review of the genus Eucalodium

Fred Thompson published recently a review of the entire genus Eucalodium Crosse & Fischer, 1868 in Archiv für Molluskenkunde. It is a paper in his style with well-written text, good figures and distribution maps.

The abstract is here copied.

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For three species anatomical details are also presented.

Reference:
Thompson, F.G., 2014. A review of the Mexican and Central American land snails of the genus Eucalodium Crosse & Fischer (Pulmonata: Urocoptoidea: Eucalodiidae). – Archiv für Molluskenkunde 143: 69-105.

New Eucalodium from Belize

At the end of the year, it is ‘rainy season’ for malacological papers. One from Thompson & Dourson (2013) describes a new species from Belize, Eucalodium belizensis. It is the first species of this genus reported from this country, where it was found in the Toledo District, north of San José.

The holotype is in the Florida States Museum, UF 44972.

Reference:
Thompson, F.G. & Dourson, D.C. (2013). A new land snail of the genus Eucalodium (Gastropoda: Pulmonata: Urocoptidae) from Belize. — The Nautilus 127: 153–155.