Empherium rasnitsyni, HAKIM & HUANG & AZAR, 2021

HAKIM, MARINA, HUANG, DI-YING & AZAR, DANY, 2021, New fossil psocids from Cretaceous Siberian ambers (Psocodea: Trogiomorpha: Atropetae), Palaeoentomology 4 (2), pp. 186-198 : 189-192

Empherium rasnitsyni sp. nov.

( Figs 2–5 )

Type material. Holotype specimen PIN 3426 /34, female, mostly well-preserved ( Fig. 2 ). Visible breaks in the amber, especially over the head area, creating a mirror effect during observation. No syninclusions observed.

Etymology. Named after Professor Alexandr Rasnitsyn.

Diagnosis. As for genus, by monotypy.

Locality and horizon. Nizhnyaya Agapa, Taimyr Peninsula, Russia, Dolgan Formation, Cretaceous (Upper Cenomanian).

Description. Head 0.70 mm wide ( Fig. 3A ); dorsal suture visible, much accentuated. Ocelli present. Compound eyes bare, as long as vertex. Antenna with 25 antennomeres, setae thin and sparse along its length, no secondary annulations; complete antenna with 23 flagellomeres, 0.01 mm wide and 0.05–0.06 mm long, last segment diminutive, with two small and thin apical setae pointing forward. Maxillary palpomeres four-segmented, setose, second palpomere with strong conical sensillum at middle ( Fig. 3B ). Labial palpomeres two-segmented. Lacinia not visible.

Thorax 0.60 mm wide; legs with tibia bearing occasional spines along its length and two apical spurs. Tarsi three-segmented ( Fig. 3C ); ratio of tarsal segments (from base to apex) in fore and mid-legs 3:1:1, in hindlegs 4.5:1:1; basal tarsomere with two rows of four spines but no ctenidiobothria ( Fig. 3D ); pretarsal claw without preapical tooth, pulvillus present (long and narrow basally but rounded, sphere-like, apically).

Wings macropterous ( Fig. 3E ); forewing (1.80 mm long and 0.50 mm wide) with marginal setae; membrane hyaline, setae arranged in two rows around veins and sparsely dispersed in some areas of membrane (e. g., pterostigma cell and anal region); Sc present, curved back and fusing with R, additional veinlet emerging from Sc and reaching costal margin; Sc’ reaching margin at 1.09 mm; pterostigma cell closed basally, 0.30 mm long and 0.10 mm wide; R 1 reaching margin at 1.30 mm from base; Rs bifurcated, R 2+3 reaching margin at 1.60 mm and R 4+5 reaching margin at apex; short crossvein r 1 -rs present; M three-branched, veins very long, M 3 separating from common stem M at 0.76 mm, stem M 1 and M 2 very short, fork M 1 and M 2 at 0.86 mm, branches M 1, M 2 and M 3 reaching margin respectively at 1.50, 1.40 and 1.18 mm; CuA bifurcated at 0.50 mm, CuA 1 and CuA 2 veins short, reaching margin respectively at 0.80 and 0.70 mm; areola postica (AP) cell free, 0.30 mm long and 0.18 mm wide; CuP and A 1 simple; A 1 weakly visible, A 2 short. Hind wing (1.38 mm long and 0.40 mm wide) without marginal setae; membrane hyaline, not setose; Sc present, short, not reaching margin; basi-radial cell present, with basal section unclear, potentially absent or weakly visible; stems R and M fused in a short segment, 0.05 mm long; R 1 branching from common stem R+M at 0.40 mm from base, reaching margin at 0.90 mm; common stem Rs as long as branches R 2+3 and R 4+5; R 2+3 reaching margin at 1.20 mm and R 4+5 at apex; M two-branched, with M 1 reaching margin at 1.20 mm; CuA simple; CuP and A not visible.

Female ovipositor with dorsal and ventral valvulae not visible; external valvulae (V3) elongated, setose ( Fig. 3F, G ); subgenital plate setose, narrowed apically, with tapered segment rounded; paraprocts with a thick posterior spine each.

Remarks. Teratology and aberrations in wing venation seem very common in this family. Within this single specimen, we observe between the pair of forewings several differences that can be attributed to teratological malformations: R 4+5 is bifurcated apically in one wing, the shape of Sc differs from one wing to the other, the Sc veinlet is aborted mid-way in one wing, and another aborted veinlet is observed on the pterostigma of the other ( Fig. 4B ).

Figures

FIGURE 2. Empherium rasnitsyni gen. et sp. nov., holotype, female. A, Habitus, dorsal view. B, Habitus, ventral view. Scale bars = 0.5 mm.

FIGURE 3. Empherium rasnitsyni gen. et sp. nov., holotype, female. A, Details of head, dorsal view. B, Details of second maxillary palpus. C, Details of tarsomeres. D, Details of apical tarsomere and claws. E, Details of wings. F, Details of abdomen. G, Details of female terminalia. Scale bars: 0.2 mm for A, E, F; 0.1 mm for C, G; 0.05 mm for B, D.

FIGURE 4. Empherium rasnitsyni gen. et sp. nov., holotype, female, drawings. A, Antenna. B, Forewing. C, Hind wing. Scale bars: 0.2 mm for A; 0.5 mm for B and C.

FIGURE 5. Empherium rasnitsyni gen. et sp. nov., holotype, female, drawings. A, Hind leg. B, Female terminalia. Scale bars = 0.2 mm.