Palaeocnopus glabricornis, Alekseev, Vitalii I. & Grzymala, Traci L., 2015

Alekseev, Vitalii I. & Grzymala, Traci L., 2015, New Aderidae (Coleoptera: Tenebrionoidea) from Baltic and Bitterfeld amber, Zootaxa 3956 (2), pp. 239-257 : 254

Palaeocnopus glabricornis sp. nov. Alekseev & Grzymala

( Figs. 23 , 30–31 )

Material examined. Holotype No. 890-2 [ CCHH], possible male (long antennae and large eyes) ( Figs. 31–32 ). The beetle inclusion is preserved in a polished piece of transparent amber with a yellowish shade and the amber piece is embedded in polyester resin. Syninclusions are absent. Paratype No. AWI-120 [ CVIA], possible male. The beetle inclusion is preserved in a polished piece of transparent amber, orange in color, without any further fixation. The piece is small, irregular in form, with maximum length 11 mm and maximum width 9 mm. Syninclusions are absent. Paratype No. AWI-122 [ CVIA], possible male. The beetle inclusion is preserved in a polished piece of transparent amber, orange in color, without any further fixation. The piece is irregular in form, with maximum length 17 mm and maximum width 13 mm. The syninclusions are represented by two trichomes.

Etymology. This species is named from a combination of Latin “ glaber ” [glabrate, hairless] and Latin “ cornu ” [horn or antenna], referring to the hairless antennae.

Type strata. Bitterfeld amber. Eocene.

Type locality. Germany, Sachsen-Anhalt, Goitzsche (Bitterfeld).

Description. Length 1.5 (paratypes)— 1.65 mm (holotype); moderately convex, elongate; uniformly light brown. Upper surface of body glabrous. Body length 2.1× maximum body width. Elytral length 4.6× pronotal length.

Head. Eyes very large and prominent, hemispherical, coarsely faceted, adjacent to hind margin of head; interocular space narrower than one ocular diameter; temples narrow; apical maxillary palpomere acute, triangular; apical labial palpomere elongate, oval. Vertex finely punctate. Antenna ( Fig. 23 B) filiform, long, 11-segmented, sparsely pubescent; reaching middle of elytra when folded backward; pedicel shortest in length, globular; apical antennomere tear-shaped (widest in second half); antennomere length ratios: 5-2.5-8-5-5-5-5-5-5-5-8.

Thorax. Pronotum transverse ( Fig. 23 A), widest posterad to middle; glabrous; finely and densely punctate; without visible pubescence; with two deep sub-triangular lateral impressions at anterior angles. Scutellum transverse, truncate. Elytron glabrous, moderately convex, slightly depressed on disc; subparallel; width 0.56× length; punctation irregular, coarse, dense, slightly rugose on disc. Elytral pubescence absent.

Abdomen. Separation of abdominal ventrite I and abdominal ventrite II well-defined laterally, obsolete and fine medially.

Legs. Metatarsomere I slightly longer than metatarsomeres II-IV combined.

Diagnosis. Palaeocnopus glabricornis sp. nov. is distinctly more robust and with a lightly colored integument when compared with other amber species of Palaeocnopus . This newly described species can be distinguished from P. s ae t i c o r ni s by the absence of setae on the antennae, absence of pubescence on the elytra, and the different ratios of the antennomeres (segment II is almost round, segment III longer than IV–VII, ultimate antennomere tearshaped). The sub-basal pronotal impressions of P. glabricornis sp. nov. are small, shallow, and pit-shaped.

Figures

FIGURES 21 – 24. Palaeocnopus spp. illustrations. 21) Palaeocnopus densipunctatus sp. nov. A. forebody, B. antenna; 22) Palaeocnopus saeticornis sp. nov. A. forebody, B. antenna; 23) Palaeocnopus glabricornis sp. nov. A. forebody, B. antenna; 24) Palaeocnopus mara sp. nov. A. forebody, B. antenna.

FIGURES 28 – 31. Palaeocnopus habitus photographs. Palaeocnopus saeticornis sp. nov. 28) Holotype, dorsal view; 29) Holotype, latero-ventral view. Palaeocnopus glabricornis sp. nov. 30) Holotype, dorsal view; 31) Holotype, ventral view. Scale bars = 0.5 mm.