A new remarkable cimicoid genus and species (Hemiptera, Heteroptera, Cimicomorpha) from mid-Cretaceous Burmese amber, with implications for its aberrant male genitalia Author Yamada, Kazutaka https://orcid.org/0000-0002-4210-6693 Institute of Natural and Environmental Sciences, University of Hyogo, Yayoigaoka 6 - chome, Sanda-shi, Hyogo 669 - 1546, Japan & Museum of Nature and Human Activities, Hyogo, Yayoigaoka 6 - chome, Sanda-shi, Hyogo 669 - 1546, Japan yamada.kaz@gmail.com Author Yamamoto, Shuhei https://orcid.org/0000-0002-4162-8457 The Hokkaido University Museum, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo 060 - 0810, Japan Author Takahashi, Yui Keio Yochisha Elementary School, Ebisu 2 - 35 - 1, Shibuya, Tokyo 150 - 0013, Japan text Fossil Record 2023 2023-01-13 26 1 27 38 http://dx.doi.org/10.3897/fr.26.e86784 journal article http://dx.doi.org/10.3897/fr.26.e86784 2193-0074-1-27 6A3587A79E5740ACB9FD753EDDBA73C5 303E295022035210A8C508424A99393D Genus Ecpaglocoris Yamada & Yamamoto gen. nov. Type species. Ecpaglocoris ditomeus Yamada & Yamamoto, sp. nov., by original designation. Etymology. The genus name is a combination of the Greek ekpaglos (= wondrous, astounding) and koris (= bug), referring to this new fossil bug possessing unique male genitalia amongst Cimicoidea ; gender masculine. Diagnosis. Body (Fig. 1 ) elongated, dorsoventrally flattened; head (Figs 1 , 3A ) porrect; labium (Figs 1D , 2B, C ) reaching middle of mesosternum; pronotum (Figs 1A, C , 3A ) with pair of long erect setae near antero-lateral and postero-lateral angles and a pair of similarly long setae behind anterior margin; pronotal callus flat, with longitudinal shallow groove on the mid-line; hemelytral membrane (Fig. 3D ) with 10 or more long, slightly curved veins; a very long trichobothrium (Figs 2E , 3D, E ) present on middle of corium-membrane boundary; ostiolar peritreme (Figs 2F , 3F ) slightly curved forward at apex, distinctly continued to a fine carina which reaches anterior margin of metapleura; fore femur (Figs 2G , 3G ) extremely enlarged; fore tibia (Figs 2G , 3G ) strongly expanded towards apex, bearing 4-5 long, stout spines and 4-5 small teeth on ventral side and with greatly developed fossula spongiosa at apex; middle and hind tibiae (Figs 1B, D , 3H, I ) with several long, stout spines, lacking fossula spongiosa; dorsal laterotergites (Fig. 2D ) not fused with mediotergites on abdominal segments I to VIII; pygophore (Fig. 4A-C ) symmetrical, longer than combined length of abdominal sterna VII and VIII in ventral view, very broadly connected to abdominal segment VIII; proctiger well-developed; parameres (Fig. 4 ) symmetrical, orientated anteriorly, very slender and long, moderately curved, acute towards apex, with groove running throughout the paramere. Figure 1. General habitus of Ecpaglocoris ditomeus gen. et sp. nov., male, holotype (AMNH Bu-SY33). A. Dorsal view; B. Left laterodorsal view; C. Ventral view; D. Right laterodorsal view. Scale bars: 0.5 mm. Differential diagnosis. The new genus Ecpaglocoris differs from the genus Pubivetanthocoris Tang, Wang & Yao, 2022 by the head shorter than pronotum (in Pubivetanthocoris , slightly longer than pronotum); vertex wider than twice the width of an eye in dorsal view (in Pubivetanthocoris , narrower than the width of an eye); lateral margin of pronotum not membranous, only carinated at antero-lateral angle (in Pubivetanthocoris , membranous, flattened and widely carinated); hemelytra parallel-sided (in Pubivetanthocoris , strongly curved); PCu and R+M absent on hemelytra (in Pubivetanthocoris , present); and fore tibia strongly expanded towards apex (in Pubivetanthocoris , slender, not expanded). Figure 2. Ecpaglocoris ditomeus gen. et sp. nov., male, holotype (AMNH Bu-SY33). A. Right antenna, laterodorsal view; B, C. Labium, ventral ( B ) and right lateral ( C ) views; D. Thorax and abdomen, right laterodorsal view; E. Trichobothrium on corium-membrane boundary of right hemelytron; F. Ostiolar peritreme and evaporatorium, left lateroventral view; G. Right fore-leg, outer view. Abbreviations: a1-4, antennal segment 1-4; dlt1-6, dorsal laterotergite 1-6; ev, evaporatorium; fs, fossula spongiosa; lr, Labrum; ls1-4. labial segment 1-4; op, ostiolar peritreme; tr, trichobothrium. Scale bars: 0.5 mm ( D ); 0.2 mm ( A-C, E-G ). Description. Male. Body elongated, dorsoventrally flattened. Head (Figs 1 , 3A ) porrect, slightly shorter than width across eyes; three pairs of long, erect trichobothria (cephalic macrosetae) on each side of anterior clypeus, near front margin of each eye and each side of vertex between eye and ocellus; anteocular region slightly longer than length of eye in dorsal view; eyes prominent, exceeding level of dorsal and ventral surfaces of head in lateral view; ocelli situated between eyes in front of an imaginary line that passes through posterior margin of eyes; vertex wider than twice the width of an eye in dorsal view; postocular region constricted, demarcated by transverse shallow furrow; neck long, smooth, highly polished. Antennal segment I (Figs 1 , 3A ) stout, exceeding apex of head, with a few short setae; prepedicellite present between segments I and II; segment II (Figs 1 , 2A , 3B ) stout, slightly thickened towards apex, about as long as head width across eyes, covered with suberect setae that are much shorter than width of the segment, intermixed with long setae that are longer than width of the segment; segments III and IV (Figs 1 , 2A , 3B ) filiform, much narrower than maximum width of segment II, equal in length, about 0.7 times as long as segment II, sparsely covered with long erect setae intermixed with short procumbent setae, longest setae much longer than twice the width of the respective segment. Labrum short, rounded at apex, not wholly covering labial segment I. Labium (Figs 1D , 2B, C , 3C ) long, reaching middle of mesosternum, weakly curving; segment I visible, much shorter than the other segments; segment II stout, basally narrowed, approximately eye length long; segment III extremely long, slightly thickened near base and gradually narrowed towards apex, approximately 3.6 times as long as segment II; segment IV much slender, half as long as segment III. Figure 3. Ecpaglocoris ditomeus gen. et sp. nov., male, holotype (AMNH Bu-SY33). A. Head and pronotum, dorsal view; B. Right antenna, laterodorsal view; C. Labium, lateral view; D. Left hemelytron, as seen in situ, not flattened; E. Trichobothrium on corium-membrane boundary of right hemelytron; F. Ostiolar peritreme and evaporatorium, left lateroventral view; G. Right fore-leg, outer view; H. Right middle leg, outer view; I. Right hind leg, inner view. Scale bars: 0.5 mm ( D ); 0.2 mm ( A-C, F-I ). Pronotum (Figs 1A, C , 3A ) nearly trapezoidal, shallowly depressed postero-medially, sparsely covered with tiny punctures, with pair of long erect setae near antero-lateral and postero-lateral angles and with pair of similarly long setae behind anterior margin; anterior margin slightly concave; lateral margin strongly angulate antero-laterally in dorsal view, densely covered with short setae; lateral carinae strongly expanded at antero-lateral angle; collar absent; callus flat, with longitudinal shallow groove on the mid-line; posterior margin deeply concave. Scutellum (Fig. 1A, B ) large, sub-equilateral, mesal length longer than basal width, weakly depressed through middle, sparsely covered with short procumbent setae, with a pair of long erect setae near lateral margin base. Hemelytra (Figs 1A, B , 3D ) parallel-sided, surpassing apex of abdomen, overall covered with short procumbent setae; claval suture, medial fracture and costal fracture clearly visible; distal end of medial fracture not contiguous with costal fracture; costal margin slightly sinuate. Membrane (Figs 1A, B , 3D ) with a cross vein running along corium-membrane boundary and 10 or more long, slightly curved veins radiating posteriorly from it; stub (processus corial) present at distal end of a cross vein; a very long trichobothrium (Figs 2E , 3D, E ) present on middle of corium-membrane boundary, the length much longer than three times that of other setae on hemelytron. Mesosternum wide, coarse, mesally with longitudinal carina. Metasternum extremely swollen, obtuse at apex. Metepisternum wide, overall occupied by evaporatorium surrounding the metathoracic scent gland. Metathoracic scent gland (Figs 2F , 3F ) with a wide ostiolar peritreme; ostiolar peritreme curved slightly forward at apex, distinctly continued to a fine carina that reaches anterior margin of metapleura while gently curving; median furrow running throughout the ostiolar peritreme. Fore femur (Figs 2G , 3G ) extremely enlarged, unarmed, much thicker than width of middle femur; fore tibia (Figs 2G , 3G ) strongly expanded towards apex, bearing 4-5 long, stout spines and 4-5 small teeth on ventral side, with well-developed fossula spongiosa at apex; middle coxae widely separated from each other; middle tibia (Figs 1B , 3H ) expanded towards apex, covered with several long, stout spines on apical two-thirds and with tibial comb at apex, lacking fossula spongiosa; hind coxae proximate with each other; hind femur thickened, slightly narrower than width of fore femur, equal to hind tibia; hind tibia (Figs 1B-D , 3I ) nearly cylindrical, densely covered with long, stout spines on apical three-fourths, with small tibial comb at apex, lacking fossula spongiosa. Tarsus three-segmented. Pretarsus of each leg with long, slender, symmetrical claws. Abdomen (Figs 1C, D , 2D ) lateroventrally covered with dense short setae; lateral margins of sterna VI-VIII densely covered with short, suberect setae intermixed with thickly setae; dorsal laterotergites (Fig. 2D ) not fused with mediotergites on abdominal segments I to VIII; sterna II and III broad, and VIII very narrow. Male genitalia (Fig. 4 ): Pygophore (Fig. 4A-C ) symmetrical, large, longer than combined length of abdominal sterna VII and VIII in ventral view, very broadly connected to abdominal segment VIII, dorsally depressed, posteriorly narrowed and rounded in dorsal view, densely covered with short, erect setae along outer margin and on posteroventral surface, lacking long trichobothria; proctiger well-developed; parameres (Fig. 4 ) symmetrical, arising from near mid-line of dorsocaudal part of pygophore, orientated anteriorly, very slender and long, moderately curved, acute towards apex, with groove running throughout paramere. Figure 4. Ecpaglocoris ditomeus gen. et sp. nov., male, holotype (AMNH Bu-SY33). A, B. Apex of abdomen, dorsal ( A ) and left laterodorsal ( B ) views; C. Pygophore with parameres, dorsal view; D. Right paramere, right lateral view. Abbreviations: lpm, left paramere; pt, proctiger; py, pygophore; rpm, right paramere; tg7-8, tergite 7-8. Scale bars: 0.1 mm.