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 † Laetopsia hydraenoides ( Prokin, Ren & Fikáček, 2010 ) comb. nov. ( Figs. 9 , 57, 61 ) Hydrophilopsia hydraenoides Prokin, Ren & Fikáček, 2010: 178 . Type locality and age. China , Liaoning Province , Shangyuan County, Chaomidian Village, Huangbanjigou [the name of the villige was misspelled in the original descirption].Yixian Formation, Jurassic-Cretaceous boundary,Late Tithonian-Berriasian, ca. 145–140 mya ( REN et al. 2010 ).An alternative dating was proposed by SWISHER et al. (1999) : Lower Cretaceous, Aptian, 124.6 mya (see REN et al. (2010) for discussion on various datings of Yixian formation). Material examined ( 3 spec. ). HOLOTYPE : CNU 2010021 (piece only). PARATYPE : CNU 2010026 (piece only).ADDI- TIONAL NON- TYPE SPECIMEN: CNU 2009089 (piece only). Redescription. Body elongate oval, 5.3–6.1 mm long ( holotype 6.1 mm ). Head with protruding eyes, frontoclypeal suture Y-shaped, with grooved median portion; anterior margin of clypeus straight; labrum transverse, tightly attached to anterior margin of clypeus; setiferous granules missing. Pronotum widest in anterior third, with distinctly angulate lateral margins; surface without setiferous granules, with median longitudinal groove; pronotal flanks narrow. Elytra with striae 1–7 darkened; scutellary stria absent. Mesocoxae contiguous, metaventrite much longer than mesoventrite. Abdomen with 5 ventrites. Legs relatively long. Note. The species may be easily distinguished from all other Laetopsia species according the distinctly angulate lateral margins of the pronotum. The additional specimen listed above is badly preserved and its assignment to the species is tentative.