Priacma tuberculosa, Tan, Jingjing, Ren, Dong & Shih, Chungkun, 2006

Tan, Jingjing, Ren, Dong & Shih, Chungkun, 2006, First record of fossil Priacma (Coleoptera: Archostemata: Cupedidae) from the Jehol Biota of western Liaoning, China, Zootaxa 1326, pp. 55-68 : 59-61

publication ID	https://doi.org/ 10.5281/zenodo.174106
DOI	https://doi.org/10.5281/zenodo.6259433
persistent identifier	https://treatment.plazi.org/id/038D87F9-FFD9-9810-7120-F91DD6EFF884
treatment provided by	Plazi
scientific name	Priacma tuberculosa
status	sp. nov.

Treatment

Priacma tuberculosa sp. nov.

( Figs. 2 View FIGURES 1 – 4 , 10–14 View FIGURES 10 – 12 View FIGURES 13 – 14 )

Diagnosis. P. tuberculosa sp. nov. can be distinguished from P. serrata in the absence of spines on edge of elytra, from P. corrupta in the mesosternum of new species without cross suture, from P. longicapitis and P. oculata in the ventral head surface of new one without grooves for inserting antennae, from P. striata in the elytron of new one without paler flecks, from P. sanzii in new one’s antennal second segment shorter than third one. New species differs from P. latidentata sp. nov. in mandibles not flattened at apex, posterior pair of dorsal head tubercles separated and elytral cells with 3 black macula on their margins, from both P. renaria sp. nov. and P. clavata sp. nov. in the pedicel of P. tuberculosa distinctly shorter than third antennomere.

Description. Body length 10.5 mm, body width 2.5 mm, elytron length 7.5 mm. Mediumsized and subcylindrical beetle, covered with tubercles ( Fig. 2 View FIGURES 1 – 4 ).

Head ( Fig. 13 View FIGURES 13 – 14 ) a little wider than long, bearing two pairs of tubercles, anterior pair of tubercles at base of antennae, conical, small, posterior ones circular, separated from each other, larger than anterior pair; eyes mediumsized; apex of mandibles not flattened, bidentate in horizontal cutting surface, cervical constriction unconspicuous.

Antennae filiform, incomplete (with 10 visible segments), less than half as long as entire insect, scape slightly oblong, pedicel 0.5 times as long as third antennomere, following segments homonomous ( Figs. 10 View FIGURES 10 – 12 , 13 View FIGURES 13 – 14 ).

Pronotum transverse, wider than head, narrowed towards base, 0.8 times as wide as long at posterior edge, anterior angles sharp, extending, without propleuron, disc of pronotum bearing two circular elevations; scutellum subtriangular.

Elytra about 1.5 times as wide as prothorax, 4 times as long as wide, with 9 rows of cells, elytral cells polygonal, with 3 black macula on their margins ( Figs. 12 View FIGURES 10 – 12 , 14 View FIGURES 13 – 14 ), elongated in distal part of elytron, approximately 34 cells formed in a row.

Ventral surface ( Fig. 11 View FIGURES 10 – 12 ) with gula rectangular, reaching posterior ridge of the head, widening posteriorly, genae widely separated ventrally. Prosternal process narrower than fore coxa, extending beyond coxae. Metaventrite oblong, 1.5 times as wide as long (at posterior margin); without longitudinal suture on metaventrite. Abdomen with 5 visible ventrites superimposing each other, narrowed from the base of fourth visible ventrite, first visible abdominal ventrite as long as last one, both of them longer than other visible ventrites, last visible ventrite 2.1 times as long as the previous one, its apex rounded.

Legs with procoxae circular, small, protrochanter large, subtriangular.

Holotype. Nearly complete adult, No. CNU –C–LB2005011 deposited in the Key Lab of Insect Evolution & Environmental Changes, College of Life Science, Capital Normal University in Beijing, China.

Locality and horizon. Collected near Chaomidian Village, Beipiao City, Liaoning Province, China; the Yixian Formation, Late JurassicEarly Cretaceous (Late Tithonian to the Berriasian).

Etymology. The specific epithet derives from the Latin noun tuberculum, i, n (a small swelling, bump, or protuberance). It refers to tubercles densely covering the body and, especially, the head.