Notocupes oxypygus Ponomarenko, 1969

STRELNIKOVA, OLESYA D. & YAN, EVGENY V., 2023, Redescriptions of the Triassic Notocupes beetles (Archostemata: Ommatidae) from Kyrgyzstan and South Kazakhstan, Palaeoentomology 6 (2), pp. 174-190 : 186-188

Notocupes oxypygus Ponomarenko, 1969

( Figs 10–12 )

Notocupes oxypygus Ponomarenko, 1969: 91 .

Material. Holotype and paratype PIN 1361 /128, part and counterpart of elytron .

Holotype. PIN 1240 /6, body part without the head, pronotum and most legs, Ketmen’ locality, Uygur District, Ketmen’ Ridge , Kyzyl-Tam spring, South Kazakhstan, Triassic.

Diagnosis. Elytron with up to 32 cells in a row; elytral cells closer to its distal half round, cells on epipleuron larger than elsewhere on elytron; base of field IV widened and with three rows of cells instead of two. Рaracoxal suture merged with posterior margin of metaventrite.

Description. Cuticular tubercle size is approximately 0.03 mm, space between adjacent tubercles is 0.02; density of cuticular sculpture is 550 tubercles per mm².

Elytron with apex not exceeding that of abdomen. Vein 2 straight, not following curved epipleuron, merging with vein 1 before elytron apex, space between vein convergence and elytron apex accommodating up to seven cells. Vein 3 straight, not following curved epipleuron. Veins 4 and 5 merge three cells before elytron apex.Elytron maximum width at its midlength. Epipleuron width ratio at elytron base and near apex 1.5. Elytron maximum width ratio to that of epipleuron 8.4. Humerus indistinct. Elytral apex rounded, not protruding posteriorly. Field I with single row of cells, other fields all with double rows; cells in field I 29; field II 25, field III 30, field IV 32, field V 23, field VI 27, VII 0–2. Maximum number of cells in row to elytral length ratio 4.3. Maculae present, varying in number from 4–5 at elytron base and apex to 7–8 at midlength. Bigger epipleural cells have more maculae embedded to cell edges. Cells in fields III and IV with 3–4 maculae near elytron base. Cells occupying more than half distance between veins, but clearly not reaching borders of veins.

Metaventrite width at posterior margin to its anterior margin ratio 1.9. Рaracoxal suture merging with posterior margin of metaventrite.

Abdomen with weakly defined relief, with transverse impressions on anterior and posterior margins of sternites II–IV. Abdomen is not narrowing at the base, narrowing posteriorly at level of sternite IV, abdominal apex acute. Sternite length ratio is 1.6:1:1.1:1:2.4.

Mesocoxae narrowly separated, weakly transverse.

Measurements (in mm). Holotype PIN 1240/6: body length estimated 10–13, width 3.8, elytral length 7.2–7.3, elytral width 1.9; paratype PIN 1361/128: elytron length 7.4, width 2.

Remarks. Additional rows of cells at the elytron base are also known for Z. alexrasnitsyni Strelnikova & Yan, 2021 . Cell rows with more than 30 cells found in N. rostratus , N. patulus Ponomarenko, 1985 , N. alienus (Tan & Ren, 2006) , Z. simpsoni Jarzembowski, 2015 and Z. alexrasnitsyni Strelnikova & Yan, 2021 . The species is similar to N. rostratus in strongly acute abdominal apex but differs in median fossa on abdominal apex and humerus indistinct. It differs from N. patulus in paracoxal suture merging with posterior margin of metaventrite; from N. alienus in epipleuron without cells; from Z. simpsoni in smaller size and elytron without colour pattern; from Z. alexrasnitsini in smaller size, wider base of epipleuron and smaller VII field with only 2 cells. N. oxypygus differs from other Triassic species in paracoxal suture merging with the posterior margin of the metaventrite, but similar to them in having dense, uniform cuticular tubercles. Differs from all other species of the genus in the relief of abdomen, in which depressions are visible not only along the anterior margin of the sternite, but also along the posterior ones.

Portion of the right elytron is most likely deformed on the holotype, due to experiencing tectonic deformation, thus the additional “line” visible between the sutural margin and vein 5 is most likely a bending zone.

Figures

FIGURE 10. Notocupes oxypygus, holotype (PIN, 1240/6, part). A, Dry photo. B, Interpretative line drawing, dorsal aspect. C, Interpretative line drawing, ventral aspect.

FIGURE 11. Notocupes oxypygus, holotype (PIN, 1240/6, counterpart). A, Wetted with 95% ethanol. B, Dry photo.C, Interpretative line drawing.

FIGURE 12. Notocupes oxypygus, paratype (PIN, 1361/128, part). A, Dry photo. B, Interpretative line drawing.