Phylogenetic re-evaluation of Discopleurus (Coleoptera: Tenebrionidae: Pimeliinae) and the description of a new species from the hyperarid Atacama Desert

Abstract

Discopleurus Lacordaire (Pimeliiinae: Stenosini) is distributed in mesic and arid habitats of Central and South America. Most of the species are only known from a few localities, which may be due to their small size and hidden lifestyle. It is assumed that Discopleurus species live at least temporarily in ant nests, a characteristic feature described from many members of the worldwide distributed Stenosini. A recent expedition to the Precordillera of the southern Atacama Desert allowed collecting specimens of a new Discopleurus species that inhabits the most arid habitat known so far for Discopleurus. This species is described here as Discopleurus atacamensis sp. n. and can easily be differentiated from the seven previously described Discopleurus species by the interrupted central keels of the head. A phylogenetic analysis of 60 morphological characters was used to revise the phylogeny of the genus. D. atacamensis is not the sister taxon of one of the three other Chilean species, but the sister to Discopleurus argentinensis which is found on the eastern side of the Andes. The range of the common ancestor may have been separated by the Andean uplift and/or associated environmental changes.