Revision of Tropopterus Solier: A disjunct South American component of the Australo-Pacific Moriomorphini (Coleoptera, Carabidae)

Abstract

Tropopterus Solier, 1849, precinctive to southern South America, is taxonomically revised. Six new species are described: T. peckorumsp. nov., T. robustussp. nov., T. canaliculussp. nov., T. trisinuatussp. nov., T. minimucrosp. nov., and T. fieldianussp. nov.Merizodus catapileanus Jeannel, 1962, is synonymized with T. montagnei Solier, 1849. Lectotypes are designated for T. montagnei, T. giraudyi Solier, T. duponchelii Solier, and T. nitidus Solier (= T. duponchelii). Tropopterus peruvianus Straneo is noted as a nomen dubium, with its identity and taxonomic placement to be substantiated via neotype designation. Phylogenetic relationships among Tropopterus spp. are hypothesized based on 37 morphological characters, the distributions of which are analyzed under the parsimony criterion, with the cladogram root established between Tropopterus and its adelphotaxon from New South Wales, Australia. Speciation in the group has occurred predominantly at a limited geographical scale relative to the overall generic distribution, with three pairs of sister species sympatric. However phylogenetic divergence between taxa in the more northern, sclerophyllous forest characterized by Nothofagus obliqua (Brisseau de Mirbel) and those occupying the Valdivian and North Patagonian Rain Forest dominated by N. dombeyi (Brisseau de Mirbel) is observed in two instances of phylogenetic history. Using specific collecting locality records, it is shown that Tropopterus beetles have been collected syntopically and synchronically with species of Glypholoma Jeannel (Coleoptera, Staphylinidae), Anaballetus Newton, Švec & Fikáček (Coleoptera, Leiodidae), Andotypus Spangler (Coleoptera, Hydrophilidae), and Novonothrus Balogh (Acari, Oribatida). These concordant ecological occurrences document a cohesive Nothofagus forest leaf-litter community. These genera plus other Valdivian Rain Forest invertebrate taxa all exhibit an Austral disjunct biogeographical pattern that corroborates trans-Antarctic vicariance between the Nothofagus forests of southern South America and Australia. Male genitalic antisymmetry is shown to be a synapomorphy of Tropopterus, though the female reproductive tract retains the plesiomorphic orientation observed in all other moriomorphine taxa.