Monthly Archives: July 2012

Photo of the day (138): Thaumastus

This picture was taken during bird-watching in the Jorupe Reserve in southern Ecuador. This Fundación Jocotoco reserve on the border of Ecuador and Peru, consists of Tumbesian dry tropical forest. On one of the trees this large species was spotted, which bears some resemblance to Lissachatina fulica. Fortunately, this is not the case; it is a Thaumastus species, which is difficult to identify without additional pictures.

Anyway, a nice picture of a beautiful snail from an interesting locality.

Thanks to Kate Richardson for sharing!

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Photo of the day (137): Cerion

This artistic photo of Cerion uva (L.) on Cura??ao was made by Carel de Haseth. It shows how specimens of the same species which are morphologically very differently can occur in the same population. 

Would there be an evolutionary advantage of being long and slender in this environment? Do these two forms still reproduce successfully? Just questions of a curious mind???

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Colombian snail catalogue

Last week a catalogue on the land and freshwater snail from Colombia has been published. The announcement (in Spanish) may be found here: http://alturl.com/n8onz; an interview with one of the authors may be found here: http://alturl.com/vh2nq.

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The claim that Colombia, with 659 species of non-marine mollusks (of which 293 endemic species), is the third richest country *in the world* seems to me a bit exaggerated. Maybe this claim can hold truth for the Neotropics, as Brazil and Peru are mentioned to be more biodiverse. This is something to be checked when I actually can read the book. Hence to be continued later…

Reference:
Linares, E.L. & Vera, M.L., 2012. Cátalogo de los moluscos continentales de Colombia. Universidad Nacional, Bogotá, 360 pp.

A new Bahiensis

Some journals publish accepted papers immediately online, often without pagination which will only be added when it appears on paper. Today I received such a paper, describing a new Bahiensis species from fossil beds in Uruguay (Cabrera & Martínez, 2012).

 The land snail family Odontostomidae has a poor fossil record, mainly from the middle Paleogene and early Neogene of Argentina. In this paper a new species of Odontostomidae from the Paleocene of Uruguay (Queguay Formation) is described. Bahiensis priscus  n. sp. represents the first record of the genus Bahiensis  Jousseaume 1877, and the oldest record for an Odontostomidae. The new species is characterized by a pupoid fusiform shell and an oval aperture with a single axial columellar fold. Present distribution of the genus indicates a tropical–subtropical environment, in high humidity rate areas.

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It is nice to see that recently more efforts have been put in research on Neotropical fossil land snails. This will certainly help to get a better understanding about their evolution and their distribution in time and space.
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Reference:
Cabrera, F. & Martínez, S., 2012. The oldest Odontostomidae (Mollusca: Gastropoda): Bahiensis priscus n. sp. (Paleocene, Uruguay). – Paläontologische Zeitschrift 

Hispaniolan Annulariidae

Recently a new paper of Watters (2012) was published on Annulariidae from the island of Hispaniola. The abstract is copied below:

Eleven new taxa of Hispaniolan Annulariidae are described: Abbottella (Abbottella) urbana new species [Fig. 1-3],  Chondropoma (Chondropoma) crystallinum new species, Chondropoma (Chondropoma) duffyhooksorum new species, Chondropoma (Chondropoma) vanattae polychroma new subspecies [Fig. 18-19], Chondropoma (Wetmorepoma)  morsecodex new species [Fig. 22-23], Parachondria (Parachondria) gettlemani new species, Articulipoma rhodei new species [Fig. 29-30], Chondropomium blaineorum new species, Chondropomium lynx new species [Fig. 39-40], Chondropomium eusarcum saonaense new subspecies, and Licina bartschi new species. Based on new material, Chondropoma (Chondropoma) manielense montivagum Bartsch, 1946, is synonymized with the nominal subspecies Chondropoma (Chondropoma) manielense manielense Bartsch, 1946 and Chondropoma (Chondropoma) quisquense sculptior Bartsch, 1946 is synonymized with the nominal subspecies Chondropoma (Chondropoma) quisquense quisquense Bartsch, 1946. Chondropoma (Chondropomium) vermiculatum sensu lato Bartsch, 1946 is moved to Crossepoma based on opercular features. The type locality of Chondropoma (Chondropomium) vermiculatum sallei Bartsch, 1946 is restricted to Cabral, Barahona Province, Dominican Republic. The type locality of Choanopoma solutum Pfeiffer, 1852 is restricted to the southern edge of Los Haitises Mountains, N of Majagual, ca. 12 km NW of Sabana Grande de Boya??, Monte Plata Province, Dominican Republic. The type locality of Chondropoma loweanum Pfeiffer, 1852 is restricted to Loma del Aguacate, Sierra Mart??n Grac??a, Barahona Province, Dominican Republic. Distributional and habitat notes are given for additional species.

Some selected pictures of the new taxa described are here reproduced.

Reference:
Watters, G.T., 2012. Hispaniolan Annulariidae (Gastropoda), primarily from the Barahona Peninsula: new taxa and notes. – The Nautilus 126: 1-14. 

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Photo of the day (135): Microceramus

Through the courtesy of François van der Hoeven, I received a photograph of a live specimen of Microceramus bonariensis (E.A. Smith, 1898).

This picture was made by Carel de Haseth during one of the weekly trips of the Archeological Working Group on the island of Curaçao. There was a shower of rain during their visit to the Spaansche Put area. Shortly after the rain, this snail was observed. “La Donna è mobile”; it doesn’t happen too often that pictures like this can be made…

Thanks to Carel and Françcois for sharing!

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Revised phylogeny of Orthalicoidea

Two years ago, we published a first phylogeny of the Orthalicoidea (Breure et al., 2010), in which we used 22 taxa and concluded on five families (with possibly the Megaspiridae as a sixth one). Since then molecular research continued and – together with Pedro Romero – we just published a revised phylogeny, using 74 taxa representing 30 genera (Breure & Romero, 2012).

Our results support previously presented hypotheses, but also give surprises in terms of unexpected topologies. Phylogenetic trees were estimated using maximum likelihood and Bayesian inference, and compared with traditional classifications. Phylogenetic estimations using three loci gave a strong support for monophyly of Orthalicoidea, as well as for some clades within this group (Bulimulidae, Bothriembryontidae, Orthalicidae, Amphibulimulidae), but not for others (Odontostomidae and Megaspiridae). In the resulting revision of the classification scheme of the Orthalicoidea, the tribe Simpulopsini is raised to family rank. This results in the division of the superfamily into seven families. 

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We also made a divergence time analysis, which suggests the origin of the superfamily around 100 million years ago. The major diversification started, however, around the Creatceous-Paleogene (K-Pg) boundary (red, dotted line in the figure below). We also tested the hypotheses that the break-up of Gondwana may explain the division within the Gondwanan clade. However, we only found evidence for the split between Australian Bothriembryon and South American Discoleus and Plectostylus, node V, is according to the known geological data of break-up of Gondwana. The other splits within this clade need hypotheses of long-distance dispersal. As land snails are generally thought not to be dispersed over long distances, despite a growing evidence to the contrary, this remains a puzzle to be solved. Note that an ancestor could have been dispersed shortly after the breaking of Gondwana was started, resulting in shorter distances than the present geography suggests.

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References:
Breure, A.S.H., Groenenberg, D.S.J. & Schilthuizen, M., 2010. New insights in the phylogenetic relations within the Orthalicoidea (Gastropoda, Stylommatophora) based on 28S sequence data. – Basteria 74: 25-31.
Breure, A.S.H. & Romero, P.E., 2012. Support and surprises: molecular phylogeny of the land snail superfamily Orthalicoidea (Gastropoda, Stylommatophora) using a three-locus gene analysis with a divergence time analysis and ancestral area reconstruction. – Archiv für Molluskenkunde 141: 1-20.  

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