Calvariomorphus-a new genus of marsh beetles (Coleoptera: Scirtidae) with remarkable elytral excitators Author Ruta, Rafał 0000-0001-8515-2385 Department of Biodiversity and Evolutionary Taxonomy, University of Wrocław, Przybyszewskiego 65, 51 - 148 Wrocław, Poland. rafal. ruta @ uwr. edu. pl; https: // orcid. org / 0000 - 0001 - 8515 - 2385 rafal.ruta@uwr.edu.pl Author Yoshitomi, Hiroyuki Ehime University Museum, Bunkyo 3, Matsuyama, 790 - 8577 Japan. text Zootaxa 2022 2022-03-24 5120 1 65 82 journal article 20083 10.11646/zootaxa.5120.1.4 95654c76-8405-45f2-bbe3-358622359c7c 1175-5326 6388863 F3C1D9EB-74C0-4BCA-95B2-2BECD7E7DF92 Calvariomorphus palauensis sp. nov. ( Figs 1C–D , 2A–B , 4C–D , 10 , 11 ) Type material. Holotype , male ( EUM ): “ Palau \ Babeldaob Is. \ 15-18.IX.2002 \ M. Sato leg.” . Paratype , male ( EUM ): “ Palau \ Babeldaob Is. \ 14-VII-2002 \ K. Takahashi ” . Paratype , female ( EUM ): “ Palau \ Babeldaob Is. \ 25-VIII-2002 \ K. Takahashi ” . Paratype , female ( EUM ): “ Palau \ Babeldaob Is. \ 31-VII-2002 \ K. Takahashi ” . Diagnosis. Small species (TL ~ 1.9–2.2 mm ), body widest in the middle of elytra, trigonium of penis distinctly shorter than parameroids, parameroids without denticles on outer margin, females with large oval excitator in apical region of each elytron. Description. Body small, TL 1.9 mm , TL/EW ~ 1.6, oval, light to dark brown, legs and antennae paler, yellowish, covered with yellowish semierect setae. Head strongly transverse, punctation sparse, punctures separated by ca. 2 diameters. Pronotum transverse, anterolateral and posterolateral angles right angled, lateral carinae almost straight, punctation sparse, similar to that on head. Angle between pronotum and elytra not marked in dorsal view. Scutellar shield subtriangular, impunctate. Elytra elongate, punctation stronger than on pronotum, punctures separated by ca. 1.0 diameter. Penis (L 0.42 mm , W 0.15 mm) elongate, symmetrical, widest at base, pala longer than parameroids, trigonium with subtriangular apex, distinctly shorter than parameroids, apices of parameroids rounded; tegmen (L 0.31 mm , W 0.20 mm) u-shaped, apices of parameres widened and armed with ca. 10 denticles; sternite IX (L 0.38 mm , W 0.24 mm) consisting of two elongate and relatively wide hemisternites, each rounded at apex, with sharp denticle; tergite VIII (L 0.50 mm , W 0.42 mm) with parameres as long as apical portion, apical margin covered with setae, apical plate with sparse microtrichia situated near apical margin; tergite IX (L 0.45 mm , W 0.52 mm) with short, apical plate, apical margin with wide u-shaped emargination, apodemes long, diverging basally, much longer than apical plate. Female. Size similar to that in males, TL 1.90–2.20 (2.09, n = 3) mm, TL/EW ~ 1.6–1.8 (1.7). Punctation of elytra stronger, each elytron with oval excitator near apex ( Fig. 4C–D ). Excitators concave, with numerous pores and setae directed to the middle of the structures. Ovipositor long (L 1.6 mm ), bursal sclerite (L 0.83 mm ) elongate, wider in posterior portion, with well visible ( Fig. 11B ) helicoidal structure, anterior portion narrower, rod-like; bursella oval, with folded structure inside (spermatophore?, Fig. 11B ), accessory gland oval, narrowing posteriorly, narrower portion with circular sclerotizations ( Fig. 11C ). Distribution. Known from the Babeldaob Is. only. Etymology. After Republic of Palau , a country where the species was recorded.