1 Departamento de Biodiversidad y Biologı´a Evolutiva, Museo Nacional de Ciencias Naturales, Madrid, Spain; 2 Museu de Cie `ncies Naturals de la Ciutadella, Barcelona, Spain; 3 Department of Physiology and Molecular Biodiversity, Institut de Biologia Molecular de Barcelona (CID, CSIC), Barcelona, Spain Phylogenetic relationships of Dalyat mirabilis Mateu, 2002, with a revised molecular phylogeny of ground beetles (Coleoptera, Carabidae) I. Ribera 1 , J. Mateu 2 and X. Belle ´s 3 Abstract Dalyat mirabilis Mateu 2002 (Coleoptera: Carabidae) is a cave species recently described from SE Spain, which, based on morphological analyses, has been related to the Promecognathinae (with one genus in western North America and four genera in South Africa). In this paper, we investigated the phylogenetic relationships of the main lineages of family Carabidae, and the placement of Dalyat among them, with the 18S rRNA full sequence and a fragment of wingless with the use of parsimony, a fast maximum likelihood algorithm (implemented in the program phyml), and Bayesian posterior probabilities. Although with wingless alone the relationships of Dalyat were not robustly supported, both with 18S rRNA and in a combined analysis there was a strong support for a sister relationship between Promecognathus and Dalyat with the three methods used. Using a molecular-clock approach the two lineages were estimated to have diverged at a similar (or slightly earlier) age than the origin of Harpalinae, known to have radiated in the Cretaceous. This is compatible with a vicariant origin of the lineage leading to Dalyat because of the isolation of the Iberian plate from Pangea in the late Jurassic to early Cretaceous. Other robust relationships within the Carabidae are the monophyly of Harpalinae (including Morionini, Peleciini and Pseudomorphini), its sister relationship with Brachininae, and the inclusion of these two subfamilies together with Scaritini and the austral Psydrinae in a strongly supported clade (the ÔhigherÕ Carabidae). Key words: Coleoptera – Carabidae – phylogeny – caves – vicariance – biogeography – Pangea Introduction Among the hyper-diverse groups of insects, the ground beetles (Coleoptera: Carabidae) are one of the relatively better studied, particularly in the western Palaearctic region. This attention has resulted in the infrequent discovery of species which could not be easily placed in existing supra-generic taxa. According to the recent catalogue of Lo¨ bl and Smetana (2003), only one of these supra-generic taxa was proposed to accom- modate a genus and species described from Europe in the 20th century: the subtribe Italodytina Jeannel, 1957 (Scaritinae: Clivinini), proposed for Italodytes stammeri J. Mu¨ ller, 1938, an Italian cave species. In the wider Palaearctic region, only two species and genera described since 1950 were placed in previously undescribed tribes or subtribes (Sinozolus and Sugimotoa, both from the eastern Palaearctic) (Lo¨bl and Smetana 2003). The discovery of Dalyat mirabilis Mateu 2002, a large-sized species found in three caves in Sierra de Gador (province of Almerı´a, SE Spain) (Mateu 2002; Mateu and Belle´s 2003), was thus really unexpected. Its deviating morphology (partly because of the presumed adaptations to the cave environment) did not allow an immediate recognition of its systematic placement, and only after preliminary analysis using the 18S rRNA sequence and a more detailed analyses of some morphological structures it could be tentatively placed among the Promecognathidae (sensu Deuve 1993, Promecognathinae according to other authors) (Mateu and Belle´s 2003). Prom- ecognathidae is a small group of five genera with a widely disjoint distribution: one genus (Promecognathus) with two species in western North America, and four closely related genera with six species in the Cape region of South Africa (Axinidium, Paraxinidium, Metaxinidium and Holaxinidium) (Lindroth 1961; Basilewsky 1963). A Cretaceous fossil from Botswana (Palaeoaxinidium) has been tentatively related to this group (McKay 1991), although the paucity of preserved characters makes difficult its taxonomic and phylogenetic placement (Mateu and Belle´s 2003). Characters supporting the relationship of D. mirabilis with Promecognathidae are the insertion of the defensive gland close to the base of the gonopod; lack of rim on the base of the elytra, which also lack scutellar striae and basal pore; lack of mandibular setae; lack of sexual dimorphism in the protarsi; and presence of an empodium among the claws (Deuve 1993; Mateu and Belle´s 2003). However, D. mirabilis differs from the known Promecognathidae in several key characters, such (among others) the lack of pubescence in the pronotum and elytra, the structure of the feeding apparatus (including the lack of galea in D. mirabilis), and the pattern of the pores and setae on the pronotum and elytra (see Mateu and Belle´s 2003 for a detailed account of the morphology of D. mirabilis and its comparison with Promecognathidae and Scaritinae). These differences, together with some morphological characters that suggested a possible relationship with Scaritinae (such the size and structure of the mandibles and the lacinia) (Mateu and Belle´s 2003), warrants the need of a more detailed study of the phylogenetic placement of this enigmatic species using a different set of characters. In this paper, we attempt to establish the phylogenetic relationships of D. mirabilis using molecular information. For that purpose the available data of two nuclear genes for a good representation of ground beetle diversity was used (complete 18S rRNA and a fragment of wingless, Maddison et al. 1998, 1999; Ober 2002), with the addition of the equivalent sequences obtained from D. mirabilis. The opportunity is taken to re-evaluate the phylogeny of the main lineages of Carabidae using different analytical methods and taxon sampling to those used originally by Maddison et al. (1998, 1999) and Ober (2002). Finally, using a molecular clock approach, we provide a temporal framework for the diversification of the basal lineages of Carabidae, including the separation between Dalyat and their Ó 2005 Blackwell Verlag, Berlin Accepted on 24 May 2005 JZS doi: 10.1111/j.1439-0469.2005.00324.284–296 JZS (2005) 43(4), 284–296