Globicornis (Globicornis) groehni, Bukejs & Háva, 2018

Bukejs, Andris & Háva, Jiří, 2018, A new species of Globicornis Latreille (Coleoptera: Dermestidae) from Baltic amber, with a key to fossil species, Zootaxa 4483 (2), pp. 395-400 : 396-399

Globicornis (Globicornis) groehni sp. nov.

( Figs. 1–5 )

Type material. Holotype: “GPIH no. 4951, coll. Gröhn no. 8587”, deposited in the Centrum of Natural History (CeNak) (formerly Geological-Paleontological Institute and Museum, GPIH) of the University of Hamburg, Germany; adult, sex unknown. Complete beetle is included in elongate, transparent amber piece, with dimensions of 65×23× 9 mm. Ventral side of specimen almost completely obscured by “milky” opacity. Syninclusions consist of one small specimen of Diptera , few stellate Fagaceae trichomes, and few small gas vesicles.

Type strata. Baltic amber, mid-Eocene to Upper Eocene.

Type locality. Baltic Sea coast, Yantarny settlement [formerly Palmnicken], Kaliningrad Region, Russia.

Differential diagnosis. Globicornis groehni sp. nov. differs from extinct species G. ambericus , G. rakovici , and G. ingelehmannae in possessing: (1) pronotum and elytra unicolorous black, and covered with black and yellowish to white setae (with paler setae forming patches); (2) antennomere 10 subtriangular with rounded apex; and (3) larger body size. See also key below.

This new fossil species differs from extant congeners of the genus in the combination of the following characters: (1) elongate-ovoid body shape; and (2) pronotum and elytra covered with bicoloured setae: black and yellowish to white (paler setae forming patches).

Description. Body shape elongate-ovoid, about 1.5× as long as wide, moderately convex; integument unicolorous black. Dorsum covered with moderately long, semierect, black setae (pronotal disc with finer and shorter setation), and with patches of paler (yellowish to white) setae: pronotum with three spots basally; each elytron with one spot basally, four spots in anteror one-third of elytral length, apparently two spots in posterior onethird, and one spot in posterior one-fifth; ventrum with shorter and denser dark setation. Total body length 3.6 mm, body maximum width 2.4 mm; pronotal length 1.0 mm, pronotal maximum width 2.1 mm; elytral length 2.6 mm, elytral maximum width 2.4 mm.

Head hypognathous, with dense and fine punctation. Frontal median ocellus present. Eyes oval, large, convex, entire. Antennae with ten antennomeres, clavate; with three antennomeres forming compact club and comprising about one-half of antennal length; scape hemispherical, large; pedicle hemispherical, slightly smaller than scape, and distinctly wider than antennomere 3; antennomeres 3–7 small, transverse; antennomeres 8–9 large, subequal in size and shape, transverse, 1.6× as wide as long, and slightly dilated apically; antennomere 10 subtriangular with rounded apex, about 1.5× as long as wide, and slightly narrower than antennomere 9.

Pronotum transverse, 2.1× as wide as long, bell-shaped, widest at base; lateral margin of pronotum widely rounded, posterior margin bisinuated; pronotal surface covered with fine punctation, distance between punctures distinctly larger than diameter of one puncture, interspaces with secondary punctures. Hypomeron with distinct antennal cavity. Prosternum with dense, small punctures; forming “collar” under which mouthparts fit when head retracted.

Scutellar shield minute, triangular with pointed apex, apparently impunctate and hairless.

Elytra about 1.1× as long as wide, widest in anterior one-third of length, narrowed posteriad, with anterior margin deeply concave, humeral callus weak; densely covered with small confused punctures (punctures distinctly larger than pronotal punctures), distance between punctures approximately 0.5–2.0× diameter of one puncture. Epipleura narrow, slightly impressed, wide at humeri and gradually narrowing toward elytral apex, not reaching elytral apex. Meso- and metasternum densely covered with moderately large punctation (distinctly larger than elytral punctures), distance between punctures less than diameter of one puncture.

Legs slender, moderately long; covered with fine punctures and short, recumbent setae. Femora flattened, with longitudinal groove ventrally. Tibia straight, subcilyndrical, about 0.5× as wide as femora, tibia and femora subequal in length; protibia without spines, slightly shorter than meso- and metatibia. Tarsi thin, moderately long, about 0.5× as long as tibiae, protarsus slightly shorter than meso- and metatarsus; relative length ratios of metatarsomeres 1–5 equal to 9- 9-7-5-13. Claws thin and long, free, simple.

Abdomen densely covered with small setae; relative length ratios of ventrites 1–5 (laterally) equal to 9-7-5-5- 7.

Etymology. The species is named in honor of Carsten Gröhn (Glinde, Germany) who provided us the species for the analysis.

Figures

FIGURES 1–3. Globicornis groehni sp. nov., holotype: 1—habitus, dorsal view; 2—habitus, ventro-caudal view; 3—habitus, lateral view. Scale bars represent 1.0 mm.

FIGURES 4–5. Globicornis groehni sp. nov., holotype: 4—details of forebody, lateral view; 5—details of right elytron, dorsal view. Scale bars represent 0.5 mm.