Early Mecopterida and the systematic position of the Microptysmatidae (Insecta: Endopterygota)

In recent times many authors have regarded the Protomeropidae and Microptysmatidae - two essentially Permian groups - as either early trichopteran lineages or members of the stem-group of the Amphiesmenoptera (basically: Trichoptera + Lepidoptera). Actually none of these families possesses, in its ground plan, the most significant derived trait of the amphiesmenopteran brewing, namely a true 'double-Y loop' arrangement of the anal veins. Since 'Carpenter's organs', small rounded structures in the costal area of the hindwing, are only known to occur in certain members of the Permochoristidae, Kaltanidae and Protomeropidae, these three families should belong to a fossil clade, which we ascribe to the Mecoptera, suborder Pistillifera sensu lato, mainly on account of a few venational features. Although we maintain the Microptysmatidae in the Mecopterida (= Panorpida, i.e. Amphiesmenoptera, Mecoptera, Diptera, and relatives), we propose to place this family in a separate order: the Permotrichoptera, n. status. Indeed, apparently, Microptysmatidae can be ascribed neither to the Amphiesmenoptera nor to the Antliophora (= Mecoptera-Diptera complex).