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Schneeberg, K. and Beutel, R.G. 2011. The adult head structures of Tipulomorpha (Diptera, Insecta) and their phylogenetic implications. -Acta Zoologica (Stockholm) 92: 316-343.Head structures of adults of Tipula paludosa, Limonia sp. and Trichocera saltator were examined and described. The results are compared with conditions found in other dipterans and other antliophoran groups, notably Nannochoristidae. Several potential synapomorphies of a dipteran-nannomecopteran-siphonapteran clade are present in Tipuloidea and Trichocera, the labro-epipharyngeal food channel, the loss of the galea and the postpharyngeal pumping apparatus. The sensorial field of the maxillary palpomere 3, a potential dipterannannomecopteran synapomorphy, is also present but modified. The presence of M. clypeolabralis, labellae and mandibular stylets are groundplan apomorphies of Diptera, with secondary loss of the mandibles in Tipuloidea, Trichoceridae and many other groups. Tipuloidea is supported by the origin of M. tentorioscapalis anterior on the head capsule, the reduction of M. frontobuccalis anterior and the loss of the ocelli. The reduced tentorium, the origin of two further antennal muscles on the head capsule, the maxillary sensorial field with sensilla in individual pits, the lacking dorsal prelabial concavity and the unpaired salivary channel entering the head are apomorphies of Tipulidae. Closer affinities of Tipulidae and Cylindrotomidae are suggested by pseudotracheae of the advanced type, which have evolved independently in this lineage. The results do neither support a basal placement of Tipuloidea nor close affinities with Brachycera.

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Pretarsal attachment structures of representatives of the megadiverse Diptera are examined and documented, mainly using scanning electron microscopy. The focus is on the basal 'nematoceran' lineages. The diversity in structures is much higher than suggested by brief summarizing accounts in earlier studies. Both hairy and smooth attachment structures occur. A well-developed, pad-like empodium with its ventral surface covered with adhesive hairs is arguably a groundplan feature of Diptera. Very often this pad is combined with the presence of hairy pulvilli. However, smooth pulvilli occur in two of the examined groups. A smooth arolium is present in Tipulomorpha and likely an autapomorphy of this clade, suggesting that it was acquired secondarily. Evolutionary transformations are interpreted based on recently published dipteran phylogenies.