Bukhkalius lindae (Jarzembowski, Wang & Zheng, 2017 )

Li, Yan-Da, Huang, Di-Ying & Cai, Chen-Yang, 2021, Revisiting the morphology and systematic placement of the enigmatic Cretaceous ommatid beetle Bukhkalius lindae (Coleoptera: Archostemata: Ommatidae), Papéis Avulsos de Zoologia 61, pp. 1-6 : 2

Bukhkalius lindae (Jarzembowski, Wang & Zheng, 2017) ( Figs. 1-3 )

Material examined: Holotype, NIGP166152 .

Redescription: Body 4.1 mm long (from anterior end of mandibles to posterior end of folded elytra), 1.4 mm wide, with moderately short setae.

Head ( Fig.3A ) prognathous,moderately elongate,distinctly flattened, constricted posteriorly to form a neck. Temples short. Posterior protuberances wide and indistinct. Compound eyes entire and finely facetted, without interfacetal setae. Antennal insertions lateral. Antennal grooves incomplete but distinct, only reaching anterior margin of eyes. Antenna short, extending beyond anterior prothoracic margin, but not reaching posterior prothoracic margin, 11-segmented and subfiliform, with thin setae; antennomere 3 slightly longer than 4. Labrum transverse. Mandible tridentate with vertically aligned teeth. Maxillary palps four-segmented, moderately long, extending well beyond apex of mandible when anteriorly directed; apical palpomere slender, not expanded, with small cavity near apex. Prementum with deep posteromedian pit. Separate mentum present, transverse. Labial palps three-segmented; apical palpomere slightly expanded, securiform. Gular sutures indistinct.

Pronotal disc longer than wide, without protuberances or ridges. Propleura probably not reaching anterior prothoracic margin, i.e., notopleural suture joined by pleurosternal suture anteriorly ( Fig. 3B ). Prosternum in front of coxae moderately long. Procoxal cavities contiguous, broadly open externally. Mesoventrite at middle with acute anterior projection separating paired procoxal rests. Mesocoxal cavities contiguous. Metacoxae strongly transverse, contiguous, extending laterally to meet elytra. Elytra 1.7 times as long as wide combined, each with ten rows of maculated window punctures; longitudinal ridges (primary veins) indistinct; lateral edge of elytra with double rows of teeth. Femora stout. Tibiae thinner; tibial spurs well-developed. Tarsi five-segmented; tarsomeres simple, not bilobed; pretarsal claws simple.

Abdomen with five coplanar ventrites, separated by wide grooves; first and fifth ventrites longer than others.

Figures

Figure 1. General habitus of Bukhkalius lindae, holotype,NIGP166152,under incident light.(A) Dorsal view.(B)Ventral view.Scale bars:1 mm.

Figure 2. General habitus of Bukhkaliuslindae, holotype,NIGP166152,under widefield fluorescence.(A) Dorsal view.(B)Ventralview.Scale bars:1 mm.

Figure 3. Details of Bukhkaliuslindae, holotype,NIGP166152,ventral view,under confocal microscopy.(A) Head,showing the possibly incomplete antennal groove (arrowhead). (B) Prothorax. Abbreviations: an1 = antennomere 1; ey = compound eye; lbp = labial palp; md = mandible; msv = mesoventrite; mt = mentum; mxp = maxillary palp;pf = profemur;pm = prementum;pp = propleuron;ps = prosternum;ptb = protibia.Scale bars:200 μm.