At home at least: the taxonomic position of some north African Xerocrassa species (Pulmonata, Geomitridae)

Abstract

In order to clarify the systematic position of Helix latastei Letourneux in Letourneux & Bourguignat, 1887, and Helix latasteopsis Letourneux & Bourguignat, 1887, a comprehensive approach using morphological and molecular methods is presented. The investigation of the genital organs of both species showed that they belong to the genus Xerocrassa Monterosato, 1892 with two very small dart sacs and a few tubiform glandulae mucosae. In our phylogenetic analysis using the mitochondrial markers COI, 16S and the nuclear cluster 5.8-ITS2-28S, the results of the anatomical research were confirmed. Thus, the genus Ereminella Pallary, 1919, which is based on H. latastei, becomes a junior synonym of Xerocrassa. A review of the genus-level taxa Xerobarcana Brandt, 1959, and Xeroregima Brandt, 1959, showed that these should also be considered as synonyms of Xerocrassa. A third species, Helix lacertara Bourguignat, 1863 from Algeria was found to be closely related to X. latastei based on its shell morphology. A map showing the distribution of the three species treated is supplied.