Revision of Mesozoic fossils of the helophorid lineage of the superfamily Hydrophiloidea (Coleoptera: Polyphaga) Author Fikáček, Martin Department of Entomology, National Museum, Kunratice 1, CZ- 148 00 Praha 4, Czech Republic; e-mail: mfikacek @ gmail. com & Department of Zoology, Faculty of Science, Charles University in Prague, Viničná 7, CZ- 128 44 Praha 2, Czech Republic; e-mail: jprokop @ natur. cuni. cz Author Prokin, Alexander Papanin Institute for Inland Water Biology, Russian Academy of Science, Borok, Russia; e-mail: prokina @ mail. ru & Voronezh State University, Research-Educational Centre “ Venevitinovo ”, Voronezh, Russia Author Angus, Robert B. Department of Entomology, The Natural History Museum, London, UK; e-mail: r. angus @ rhul. ac. uk Author Pono, Alexander Author Marenko Borissiak Paleontological Institute, Russian Academy of Sciences, Moscow, Russia; e-mail: aponom @ paleo. ru Author Yue, Yanli School of Life Science, Ningxia University, Ningxia, China; e-mail: yueyanli 0407 @ yahoo. cn Author Ren, Dong Author Prokop, Jakub Department of Zoology, Faculty of Science, Charles University in Prague, Viničná 7, CZ- 128 44 Praha 2, Czech Republic; e-mail: jprokop @ natur. cuni. cz text Acta Entomologica Musei Nationalis Pragae 2012 2012-06-30 52 1 89 127 journal article 10.5281/zenodo.5330604 0374-1036 5330604 † Zetemenos sexlineatus Bode, 1953 ( Figs. 93 , 119 ) Zetemenos sexlineatus Bode, 1953: 230 . Zetemenos sexlineatus : PONOMARENKO (1992: 186) . Type locality and age. Germany , Niedersachsen , Grassel at Braunschweig (current GPS coordinates: 52.4°N 10.6°E . Posidonia Shale Formation, Early Jurassic, Early Toarcian, 183.0–182.0 mya ( CLAPHAM 2011b ). Material examined. HOLOTYPE : SMF VI 1399 (piece only). Taxonomic note. The holotype , which is the only available specimen of this species, is a badly preserved fossil in dorsal view showing an elongate beetle with striate elytra. Other characters are not preserved, except for the abdomen with five ventrites, narrow and elongate metepimera, and possibly the frontoclypeal suture (however, the impression on the head may also represent some ventral head structures). The latter character would be also the only possible indication of the position of the species in the Hydrophiloidea . However, due to the bad preservation we do not consider this character as adequate to justify the superfamily assignment of the fossil. For that reason, the species including the currently monotypic genus Zetemenos Bode, 1953 to which it belongs are excluded from the Hydrophiloidea and transferred to Coleoptera incertae sedis .