Molecular phylogeny of recognised Thai Landouria species (Gastropoda, Camaenidae), with descriptions of two new species

The molecular phylogeny and morphological – anatomical characteristics of the terrestrial snail genus Landouria Godwin-Austen, 1918 from Thailand are investigated, and we describe two new species. Phylogenetic analysis of 11 recognised Thai Landouria species reveal that these species are phylogenetically well separated from each other by mtDNA phylogeny and COI sequence divergences of 0.048 –0.192. Landouria tumpeesuwanorum sp. nov. is described from a limestone hill in Nong Bua Lamphu Province, northeastern Thailand; it is characterised by its angulated whorls, a strongly keeled shell, and small flagellum with curved ends.

The second new species, Landouria flagellolonga sp. nov. is described from a limestone hill in Sa Kaeo Province, eastern Thailand. It has a conical-lenticular, sharply keeled shell, and a very long, slender flagellum.