Glabrimycetoporus Yue, Zhao & Ren

Yue, Yanli, Zhao, Yunyun & Ren, Dong, 2009, Glabrimycetoporus amoenus, a new tachyporine genus and species of Mesozoic Staphylinidae (Coleoptera) from Liaoning, China, Zootaxa 2225, pp. 63-68 : 64-66

Glabrimycetoporus Yue, Zhao & Ren gen. nov.

( Figs. 1 , 2 )

Type species. Glabrimycetoporus amoenus gen. et. sp. nov.

Description. Head oval in outline with length greater than width; narrower than pronotum, widest at base, slightly inserted into pronotum; without neck; antenna long, reaching just beyond posterior margin of pronotum if stretched posteriad, segment 1 a bit longer and wider than segment 2, segments 6–8 each slightly shorter than preceding, segments 8–10 of equal length, segment 11 1.5 times longer than segment 10; labrum with anterior margin arcuate; frontoclypeal suture distinct and broad; labial palpus with last palpomere only slightly thinner than penultimate palpomere.

Pronotum transverse, length/width ratio 0.60, sides broadly arcuate, widest just before basal angles, narrowed to apex, anterior margin truncate, anterior angles round, basal margin broadly, slightly arcuate, basal angles obtuse.

Legs long, meso- and metatibiae with 2 moderately long spurs, pro- and mesocoxae elongate, metacoxae broadly expanded, plate-like, metatrochanter subconical, protarsi with first four segments dilated, last segment longest, slightly shorter than first three segments combined.

Elytra: length along suture 1.4 times longer than pronotum at midline, sides gradually widened posteriad.

Abdomen elongate, sides evenly tapering from base to acute apex, all abdominal segments covered with dense microsetae.

Male: ninth tergite composed of two broadly separated lobes connected anteriorly, tenth tergite broad, oblong; aedeagus with median lobe elongate, parameres narrower than median lobe.

Female unknown.

Comparison. The new genus described here can be placed in the subfamily Tachyporinae based on the following characters: head more or less inserted into prothorox, lacking distinct neck, antennal insertions exposed, located anterior to a line drawn between anterior edges of eyes, abdomen with six visible sterna and one pair of paratergites per segment, protarsi with five segments. The genus may belong to the tribe Mycetoporini of the subfamily Tachyporinae , based on its elongate body; head strongly tapering anteriad, and the tenth tergite broad, oblong. The typical characters of Mycetoporini are as following: head with distinct ridge below eyes, elytron with impressed sutural stria, pronotal hypomeron strongly inflexed and not visible in lateral view, postcoxal process absent. These characters are not clearly preserved in this specimen, which is the only one found in the Yixian Formation so far. We assign the new genus to Mycetoporini provisionally.

At present, the tribe Mycetoporini includes ten extant genera: Bolitobius Leach in Samouelle, 1819, Bolitopunctus Campbell, 1993 , Bryophacis Reitter, 1909 , Bryoporus Kraatz, 1857 , Carphacis Gozis, 1886 , Ischnosoma Stephens, 1829 , Lordithon Thomson, 1859 , Mycetoporus Mannerheim, 1830 , Neobolitobius Campbell, 1993 , and Parabolitobius Li, Zhao & Sakai, 2000 . Among these genera, the new genus shows significant similarities to the extant genus Bryoporus in having the antenna reaching just beyond the posterior margin of the pronotum, the metacoxae broadly expanded and plate-like, the elytra along the suture 1.4 times longer than the pronotum at midline. The new genus differs from Bryoporus in a number of significant characters: the apical segment of the labial palpi not subparallel, evenly narrowed from base to apex; antennal segments five to ten approximately of equal length, first four segments of protarsi dilated.

Etymology. The generic name is a combination of Latin adjective glaber (referring to the smooth elytra) and generic name Mycetoporus . The gender is masculine.

Figures

FIGURE 1. Glabrimycetoporus amoenus Yue, Zhao & Ren gen. et sp. nov., line drawings of the holotype. A—ventral view, No. CNU-COL-LB 2007501 C; B—dorsal view, No. CNU-COL-LB 2007501 P; C—head; D—apex of the abdomen with exposed aedeagus.

FIGURE 2. Glabrimycetoporus amoenus Yue, Zhao & Ren gen. et sp. nov., photograph of the holotype. A—part; No. CNU-COL-LB 2007501 P; B—counterpart, No. CNU-COL-LB 2007501 C; C—apex of the abdomen with exposed aedeagus, No. CNU-COL-LB 2007501 C; D—head, No. CNU-COL-LB 2007501 C.