A new genus and two new species of fossil Elaterids from the Yixian Formation of Western Liaoning, China (Coleoptera: Elateridae) Author Chang, Huali Author Zhang, Fan Author Ren, Dong text Zootaxa 2008 1785 54 62 journal article 10.5281/zenodo.182430 50abfee8-8d3a-46e1-a0a1-f3d31bab3166 1175-5326 182430 Paralithomerus parallelus sp. nov. ( Figs. 11–15 ) Type specimen : Holotype . CNU-C-LB2006872, an impression of elaterid with almost complete body, but most antennal segments absent, housed in Key Lab of Insect Evolution & Environmental Change, Capital Normal University, Beijing, China . Locality and horizon . Collected from 2nd Bed of Yixian Formation in Huangbanjigou, near Chaomidian Village, Shangyuan County, Beipiao City, Liaoning Province, China ; Upper Jurassic-Lower Cretaceous. Etymology . Specific name derived from Latin “ parallelus ”, (meaning “parallel”), for the striae of the elytra that are parallel to each other. Diagnosis . This new species is distinguished from P. exquisitus by the following characters: (1) pronotum width shorter than length if the length is measured at the median line; (2) prosternal process quite short; (3) metepisternum narrow; (4) elytra with 9 distinct longitudinal striae, each stria nearly parallel to the sutural margin, the 3rd and 4th, 7th and 8th not united; and (5) apical ventrite 1.33 times longer than the previous one and broadly rounded apically. Description . Body subcylindrical, medium sized, with length 12.5 mm, width 4.5 mm, elytron length 7.8 mm; Elytra with nine nearly parallel longitudinal striae ( Figs. 11, 13 , 14 ). Head sub-triangular, convex; eyes oval, medium sized; mandibles incurved, bidentate at apex; labrum small, transverse ( Fig. 11 ). FIGURES 11–13. Paralithomerus parallelus sp. nov. , 11 — dorsal view, 12 — prothorax, 13 — apical half of elytron. Pronotum subtrapezoidal, 2.17 times as long as head, width 1.23 times wider than long; anterior margin arched inside, with short angles, lateral sides slightly arcuate in front of hind angles, basal margin bisinuate, with basal pleural furrow; disc slightly convex, with a mild median longitudinal depression; hind angles acute, produced posteriorly, with distinct short carina ( Figs. 11, 12 ). Elytra wider than prothorax, 3.45 times as long as wide, with 9 distinct longitudinal striae, each stria nearly parallel to the sutural margin, apex of elytra slightly obtuse; epipleural rim normal ( Figs. 13 , 14 ). Ventral surface with chin piece normally arcuate; pronotosternal suture double, widely opened anteriorly; procoxal cavities quite small, rounded and separated, open behind; prosternal process short, wedge-shaped; Mesoventrite small, mesoventral cavity circular, mesepimeron subtriangular, mesocoxae open to mesepimeron. Metaventrite and mesoventrite separated by distinct suture, metaventrite relatively long and flat, with longitudinal suture; metepisternum narrow; metacoxal plates slender, obtusely long triangular, evenly narrowed laterally. Abdomen with 5 visible ventrites, narrowed from the base of fifth visible ventrite, apical ventrite 1.33 times longer than ventrite 4 and broadly rounded apically ( Figs. 12 , 15 ). Legs with procoxa rounded; mesocoxa circular, larger than procoxa, metacoxa transverse ( Fig. 11 ). Remarks . Although most of the antennal segments are absent, the new species can be assigned to the new genus Paralithomerus based on the following characters: (1) head subtriangular, convex; (2) pronotosternal sutures double, open anteriorly; (3) mesocoxae open to mesepimeron; mesoventrite and metaventrite separated by distinct suture; and (4) metacoxal plates slender, obtusely long triangular, evenly narrowed laterally.