Land snail diversity in a threatened limestone district near Istanbul, Turkey

The limestone meadows located to the north­-northwest of Istanbul, Turkey, are in danger of being overrun by the rapidly expanding city. Past surveys showed that these habitats harbor rare plant species, including endemics to Turkey. To further evaluate the conservation value of these habitats, especially in terms of the often neglected invertebrates, one limestone area to the north of Küçükçekmece Lake and surrounding Sazlidere Dam was surveyed for land snails. Our findings strengthen the case for the protection of these unique habitats. Twenty­-four species of land snails were identified in the survey area. Of these, 21 are native to Turkey, including three whose type location is Istanbul. In addition, two species that are at or near the limits of their ranges are considered to represent peripheral populations that may be especially worth conserving. Although the area surrounding Sazlidere Dam is under protection, the other limestone habitats are severely threatened by ongoing development

Diversidad de los caracoles terrestres en una zona caliza amenazada cercana a Estambul, Turquía

The limestone meadows located to the north–northwest of Istanbul, Turkey, are in danger of being overrun by the rapidly expanding city. Past surveys showed that these habitats harbor rare plant species, including endemics to Turkey. To further evaluate the conservation value of these habitats, especially in terms of the often neglected invertebrates, one limestone area to the north of Küçükçekmece Lake and surrounding Sazlidere Dam was surveyed for land snails. Our findings strengthen the case for the protection of these unique habitats. Twenty–four species of land snails were identified in the survey area. Of these, 21 are native to Turkey, including three whose type location is Istanbul. In addition, two species that are at or near the limits of their ranges are considered to represent peripheral populations that may be especially worth conserving. Although the area surrounding Sazlidere Dam is under protection, the other limestone habitats are severely threatened by ongoing development.Las praderas calcáreas situadas al NNO de Estambul están en peligro de ser rápidamente invadidas por la ciudad en expansión. Estudios anteriores demostraron que estos hábitats albergan especies vegetales raras, incluyendo algunos endemismos turcos. Con objeto de seguir evaluando el valor conservativo de dichos hábitats, en especial en cuanto a los invertebrados, a menudo ignorados, se han estudiado los caracoles terrestres de una zona calcárea al norte del lago Küçükçekmece y alrededor de la presa Sazlidere. Nuestros descubrimientos enfatizan la necesidad de una política de protección de estos hábitats únicos. En el área estudiada se identificaron 24 especies de caracoles terrestres. De ellas, 21 son nativas de Turquía, incluyendo tres cuya localización tipo es Estambul. Además, se considera que dos especies que se hallan en o cerca de los límites de su zona de distribución representan poblaciones periféricas especialmente merecedoras de conservación. A pesar de que la zona que rodea a la presa Sazlidere está protegida, el resto de los hábitats calcáreos está muy amenazado por el creciente desarrollo

Phylogeography of a Land Snail Suggests Trans-Mediterranean Neolithic Transport

Background: Fragmented distribution ranges of species with little active dispersal capacity raise the question about their place of origin and the processes and timing of either range fragmentation or dispersal. The peculiar distribution of the land snail Tudorella sulcata s. str. in Southern France, Sardinia and Algeria is such a challenging case. Methodology: Statistical phylogeographic analyses with mitochondrial COI and nuclear hsp70 haplotypes were used to answer the questions of the species' origin, sequence and timing of dispersal. The origin of the species was on Sardinia. Starting from there, a first expansion to Algeria and then to France took place. Abiotic and zoochorous dispersal could be excluded by considering the species' life style, leaving only anthropogenic translocation as parsimonious explanation. The geographic expansion could be dated to approximately 8,000 years before present with a 95% confidence interval of 10,000 to 3,000 years before present. Conclusions: This period coincides with the Neolithic expansion in the Western Mediterranean, suggesting a role of these settlers as vectors. Our findings thus propose that non-domesticated animals and plants may give hints on the direction and timing of early human expansion routes

Environmental conditions at the Last Interglacial (Eemian) site Neumark‐Nord 2, Germany inferred from stable isotope analysis of freshwater mollusc opercula

Mollusc biogenic carbonates are valuable records of past environmental conditions. In particular, carbonate oxygen (δ18O) and carbon (δ13C) stable isotopes can be used to reconstruct different physical and chemical parameters, according to the different genera used (marine, freshwater or terrestrial). The Last Interglacial (early Eemian) palaeolake of Neumark-Nord 2 (NN2), Germany provides an excellent example of a Neanderthal archaeological site with abundant freshwater carbonate remains. As in other European contexts, one of the most abundant species is Bithynia tentaculata. In order to provide a robust regional baseline for the interpretation of the archaeological data, this study includes a calibration phase on modern B. tentaculata opercula. The results indicate that these calcitic structures are likely to be subjected to a growth slowdown/cessation during summer, which influences their geochemistry, reflecting mainly the water properties of the rest of the year. This modern calibration, together with the existing palaeoenvironmental reconstructions developed for NN2 (e.g. pollen data), represents a valuable opportunity to establish B. tentaculata opercula as reliable environmental proxies applicable to several other freshwater contexts. The isotope data of the NN2 opercula, in agreement with the pollen record, indicate that the major archaeological horizon was formed during a rather wet period and potentially in a semi-forested environment. However, human occupation occurred also during drier phases at the site and within a wide temperature range, indicating the absence of restricted environmental preferences by the local Neanderthal groups