New fossil Priacmini (Insecta: Coleoptera: Archostemata: Cupedidae) from the Jehol Biota of China Author Tan, Jingjing Author Ren, Dong text Journal of Natural History 2006 2006-12-30 40 47 - 48 2653 2661 http://dx.doi.org/10.1080/00222930601121445 journal article 10.1080/00222930601121445 1464-5262 5230228 Priacmopsis subtilis sp. nov. ( Figure 1 ) Type material Holotype : Collected near Chaomidian Village , Beipiao City , Liaoning Province , China ; the Yixian Formation , Late Jurassic-Early Cretaceous (Late Tithonian to Berriasian), two specimens , part and counterpart of a near complete adult, No. CNU-C-LB2006003-1 and No. CNU-C-LB2006003-2, housed in Key Lab of Insect Evolution and Environment Change , Capital Normal University , Beijing , China . Diagnosis Distinct from the type species in having a smaller size and convex anterior margin of pronotum, from P. minimus Ponomarenko, 1997 in that the ventral surface of the new species is without a groove for inserting antennae and less than 40 elytral cells in a row. Description Body length 11.5 mm , body width 3.0 mm, elytron length 8.0 mm. Medium and subcylindrical beetles, covered with tubercles ( Figure 1A ). Head: wider than long, subtriangular, bearing two pairs of tubercles, anterior pair of tubercles at base of antennae, conical, small, posterior ones half-moon shaped, larger than anterior pair, ventral surface without groove for inserting antennae; eyes small; temples as long as eyes, projected laterally; mandibles prominent, broad, apex flattened, tridentate ( Figure 1B ), cervical constriction distinct. Antennae: filiform, 11 segments, scape thicker than other antennomeres, both scape and last antennomere longer than other segments, pedicel shortest, slightly longer than wide, following antennomeres more or less homonomous. Pronotum: transverse, slightly wider than head, about 1.1 times as wide as long, anterior margin convex forward, anterior angle rounded, without propleuron, disc of pronotum bearing two quadrate elevations; scutellum linguiform. Elytron: about 1.6 times as wide as prothorax, longitudinal ridges with small tubercles, 4.1 times as long as wide, epipleural rim narrow, with 10 rows of cells, elytral cells oblong, without black maculae on their margins ( Figure 1D, E ), approximately 35 cells formed in a row. C E Figure 1. Priacmopsis subtilis sp. n. , holotype No.CNU-C-LB2006003-1. (A) Photograph; (B) line drawing of dorsal view; (C) line drawing of ventral view; (D) outline of elytral cell; (E) photograph of elytral cell. In all figures, scale bars52.0 mm. Ventral surface ( Figure 1C ): gula rectangular, reaching posterior ridge of head, widening posteriorly, gena widely separated along entire distance ventrally; procoxal cavities separated, prosternal process extending behind coxae; metasternum trapezoidal, transverse, 1.5 times as long as wide (at posterior margin), without longitudinal suture developed on metasternum. Abdomen with five visible ventrites over lapping each other, narrowed from the base of forth visible ventrite, first visible abdomen ventrite longer than others, two to four visible abdomen ventrites equal in length, last visible ventrite 1.8 times as long as the previous one, its apex rounded. Legs: procoxae rounded, small, protrochanter semicircular, profemora shorter than protibiae; mesocoxae oblong, mesotrochanter small, circular, mesotibiae as long as mesofemora, mesotarsi with five elongate, unmodified tarsomeres, first tarsomere longer than others, the rest nearly equal in length; metafemora short, not extending beyond side margins of body. Geographical distribution Known only from China .