New palaeodictyopterans from the Late Carboniferous of the UK (Insecta: Palaeodictyopterida)

Abstract

ABSTRACTNew palaeodictyopterans, Vernooijia sassoonae gen. et sp. nov. (Breyeriidae) and Mazonopterumcooperi sp. nov. (Homoiopteridae) are described from the Middle Pennsylvanian (Westphalian D/Late Asturian) of Writhlington, near Radstock (UK). Based on the re-examination of venation in Breyeriaharlemensis, we propose the transfer of this species to the genus Vernooijia as V.harlemensis (Brauckmann & Gröning, 1996) comb. nov. We report the first record of Homaloneura sp. (Spilapteridae) from the Langsettian to Duckmantian of Coseley, Staffordshire. Additionally, we report a fragmentary wing from the Middle Pennsylvanian (late Westphalian D/early Cantabrian) of the Forest of Dean, Gloucestershire, tentatively belonging to the Lycocercidae. Our re-examination of a putative blattodean nymph described by Rolfe (1967) allows re-assignment to Palaeodictyoptera, as it has well-developed wing pads with a corrugated pattern of probably original tracheation and lacunal channels, identified as presumably nymphal exuvia of Idoptilus sp. Surprisingly, our study reveals the presence of three triangular caudal appendages bearing prominent lateral lamellae emerging from the terminal abdominal segment, previously unknown in other nymphs of Palaeodictyoptera. We assume that these lamellae were originally covered with dense setae and possibly represent modified caudal appendages in the form of tracheal gills, as known in the nymphs of damselflies (Odonata: Zygoptera). Thus, the scenario of a possible aquatic lifestyle for nymphs of at least some members of Palaeodictyoptera, as considered by Brongniart (1885, 1893) and Handlirsch (1906), cannot be definitely excluded.