The subtribes and genera of the tribe Broscini (Coleoptera : Carabidae): Cladistic analysis, taxonomic treatment, and biogeographical consideration

Phylogenetic relationships of the genera of the tribe Broscini (Carabidae) are postulated based on cladistic methods. Seventy-three morphological char acters were examined in 88 species, arranged in 41 genera and subgenera, an d with the related tribes Melaenini and Apotomini as outgroups. In all the obtained cladograms, the genera are grouped in five clades recognized as th e basis for a new subtribal classification: the Oriental-Palearctic-Neotrop ical Axonyina, new subtribe (type genus, Axonya Andrewes) with 3 genera; th e Holarctic-Oriental subtribe Broscina (type genus Broscus Panzer) with 9 g enera; the south temperate Australian-Neotropical Nothobroscina new subtrib e (type genus Nothobroscus Roig-Junent and Ball) with 10 genera; the south temperate Neotropical Barypina (type genus Barypus Dejean) with 2 genera; a nd the south temperate Australian-Neotropical Creobiina (type genus Creobiu s Guerin-Meneville) with Il genera. Species groups within diverse genera Ba rypus, Eurylychnus Bates, and Promecoderus Dejean were treated as terminal units to test monophyly of these genera. Results of the analysis show that only Promecoderus is not monophyletic, as presently structured. Keys and di agnoses are provided for the genera of Broscini, and all taxonomically impo rtant structures are illustrated. Genital features of males and females are described for the first time for several genera. The barypine genus Microb arypus, with its type species M. silvicola (type locality Alto Queulat, Ais en, Chile) is described as new. The species Percosoma concolor Sloane, P. s ubstriatum Moore, and P. montanum Castelnau are transferred to the genus Ch ylnus. Type species are designated for Adotela Castelnau (Adotela concolor Castelnau), Gnathoxys Westwood (Gnathoxys granularis Westwood), and Cerotal is Castelnau (Cerotalis substriata Castelnau). The four main biogeographica l hypotheses proposed to explain Broscini distribution are discussed. Recen t discovery of new Neotropical genera, as Nothobroscus Roig-Junent and Bah and Rawlinsius Davidson and Ball, together with the phylogeny of Broscini, lead to a different biogeographic hypothesis. Broscini can be considered a Pangaeic tribe originating in lower Jurassic times when there was a land co nnection between South America and North America on the Pacific margin. In broad terms, the biogeographic pattern of Broscini may be explained by the current hypothesis of the breakup of Pangaea.