Abstract

The tribe Leptodirini of the beetle family Leiodidae is one of the most diverse radiations of cave animals, with a distribution centred north of the Mediterranean basin from the Iberian Peninsula to Iran. Six genera outside this core area, most notably Platycholeus Horn, 1880 in the western United States and others in East Asia, have been assumed to be related to Lepto- dirini. We studied recently collected specimens of three of these extraterritorial genera, namely Platycholeus, Fusi Perkovsky, 1989 and Sciaphyes Jeannel, 1910, and establish their phylogenetic relationships by analysing a combination of ca. 5 Kb of mitochondrial and nuclear DNA sequences with Bayesian Probability and Maximum Likelihood methods. Our results cor- roborate the previously proposed hypothesis that Platycholeus is the sister group of the remaining Leptodirini, with an esti- mated age of vicariant separation compatible with the breaking of the Thulean bridge between the Nearctic and the Western Palaearctic in the Early Eocene. We refute close relationship of either Fusi or Sciaphyes to Leptodirini, with the former ge- nus appearing more closely related to Cholevini, and the latter to Anemadini and warranting a separate tribe, Sciaphyini, in agreement with recent treatments. This phylogenetic position of Sciaphyes is in agreement with a parsimony analysis of 28 morphological characters of a representative sample of Cholevinae subgroups. We describe one of the studied Sciaphyes species as S. shestakovi sp. n. and indicate its remarkable morphological differences from its congeners. We hypothesise that the remaining three extraterritorial monotypic genera of “Leptodirini”, namely Proleptodirina Perkovsky, 1998, Sinobathys­ cia Perreau, 1999 and Coreobathyscia Szymczakowski, 1975 are unlikely to be closely related to the tribe, which probably has its easternmost geographical limits at Zagros and Alborz (= Elburz) mountains in Iran.