The Phylogeny of Archostemata (Coleoptera) and new Approaches in Insect Morphology Zur Phylogenie der Archostemata (Coleoptera) und neue Ansätze zur Insektenmorphologie

Abstract

This study gives an overview of recent developments and results in the morphological and phylogenetic study of Archostemata, and a short account of innovative morphological techniques such as for instance micro computer tomography (μ-CT) and computer based 3-dimensional reconstructions. Archostemata are a small relict group of beetles. They display a mosaic pattern of highly derived characters, mainly of the head, and of plesiomorphic features, mainly of the thorax. The results of recent cladistic analyses suggest that Ommatidae, Cupedidae, Micromalthidae, Crowsoniellidae and Jurodidae (Sikhotealinia and †Jurodes), and the extinct families †Schizophoridae, †Catiniidae, and tAdemosynidae form a clade Archostemata. However, the placement of Jurodidae and the three fossil groups remains ambiguous, mainly due to lack of reliable morphological data. Within Archostemata, Ommatidae are probably the most basal group and recent cladistic analyses suggest that Jurodidae may form the sistergroup of a clade comprising Micromalthidae, Crowsoniellidae, †Schizophoridae, tCatiniidae, and †Ademosynidae. Archostemata is the sistergroup of the remaining three beetle suborders. All Permian fossil lineages traditionally assigned to Archostemata belong to the stem group of Coleoptera, with a branching pattern (†Tshekardocoleidae + (†Permocupedidae + (†Rhombocoleidae + (tTriadocupedinae + (Coleoptera s.str. [=crown group]))))). The reconstruction of the phylogeny of Archostemata is still impeded by a severe lack of material and morphological data. Intensive collecting activities should have high priority, combined with the application of traditional and modem morphological methods. Innovative techniques have given new and strong impulses to insect morphology in the last years.