GEOGRAPHIC AND ECOLOGICAL PATTERNS IN TURKISH LAND SNAILS

The distribution of Turkish land snails has been examined, using data from a monograph by H. Schutt (1993). Turkey has been divided into eig ht regions for purposes of describing localization of fauna. On averag e, species occupy 1.7 regions. About 36% of the fauna is known from Tu rkey alone. There are affinities with Europe, the Caucasus, the easter n Mediterranean and the Levant and Middle East. The influence of neigh bouring faunas shows up when the similarities of the eight regions are clustered. As usual, the fauna contains a high spired and a discoidal mode of shell shape, with species covering a wide range of sizes. Cla usiliacea occupy a higher mode than other high spired species, while H elicacea become progressively more equidimensional from small to large species. The pattern of shell size and shape varies between regions, smaller and high spired species being most common in cooler and damper parts, larger discoidal species in parts with Mediterranean or contin ental dry climates. A test for evidence that animals of the same shape and size are more likely to be allopatric than sympatric failed to sh ow that they were. The fauna is dominated by a few families to a great er extent than that of Europe, and is more like that of the isolated M adeiran archipelago. It is suggested that the Turkish fauna still show s evidence of external penetration with some local radiation, in the m anner of the oceanic islands, and has not evolved to become a balanced assemblage such as is seen in Europe.