Murcybolus longiantennus Li & Cai, 2021

Li, Yan-Da, Tihelka, Erik, Huang, Diying & Cai, Chenyang, 2021, Murcybolus gen. nov., a new net-winged beetle genus from mid-Cretaceous Burmese amber (Coleoptera: Lycidae: Burmolycini), Zootaxa 4966 (1), pp. 77-83 : 78-80

Murcybolus longiantennus Li & Cai sp. nov.

( Figs 1–3 )

Etymology. The specific name refers to the beetle’s relatively long antennae.

Material. Holotype, NIGP173914 , adult female.

Locality and horizon. Amber mine located near Noije Bum Village, Tanai Township, Myitkyina District, Kachin State, Myanmar; unnamed horizon, mid-Cretaceous, Upper Albian to Lower Cenomanian .

Diagnosis. As for the genus.

Description. Adult female. Body presumably weakly-sclerotised, slender, almost parallel-sided, 2.2 mm long and 0.6 mm wide at humeri, covered with long fine hairs.

Head including eyes wider than anterior margin of pronotum, hypognathous, without any longitudinal grooves; exposed portion in dorsal view 0.21 mm long. Compound eyes lateral, large, strongly protuberant, finely faceted, without interfacetal setae. Antennal insertions located frontally, separated by projecting frontal part of cranium. Antennae moderately long, longer than half of body, with 10 antennomeres; antennomere 1 robust, with oblique apical margin; antennomere 2 short, about 0.4 times as long as antennomere 3; antennomeres 3–10 elongate, filiform, slightly asymmetrical. Mouth cavity rounded. Labrum free, located inside mouth cavity. Mandibles simple, gradually curved mesally. Maxillary palps 4-segmented; palpomere 1 short, palpomeres 2–4 filiform. Mala welldeveloped, setose. Labial palpi 3(?)-segmented.

Pronotal disc narrower than elytra, 0.27 mm long, 2.0 times as wide as long, subtrapezoidal; anterior angles obtuse; posterior angles acute, projecting laterally; surface without longitudinal carinae, with irregular deep rounded punctures. Prosternum strongly transverse, short; prosternal process narrow and acute apically. Scutellum well-developed, parallel-sided, with posterior margin emarginate. Metaventrite large.

Elytra parallel-sided, 1.7 mm long, about 2.7 times as long as their combined width, completely covering abdomen; apices separately rounded; surface with eight longitudinal costae and nine rows of rounded cells in intercostal intervals; costae 2 and 3 (counted from elytral suture outwards) interrupted in posterior quarter of elytra. Hind winds fully developed. Legs slender; procoxae narrowly separated; trochanters obliquely attached to femora; both femora and tibiae slender; tarsi with five tarsomeres, tarsomeres 1–4 subequal, tarsomere 5 slender, long; pretarsal claws simple.

Abdomen with seven free subequal ventrites.

Figures

FIGURE 1. General habitus of Murcybolus longiantennus gen. et sp. nov., female, holotype, NIGP173914, under incident light. A, Dorsal view. B, Ventral view. Scale bars: 500 μm.

FIGURE 2. General habitus of Murcybolus longiantennus gen. et sp. nov., female, holotype, NIGP173914, under widefield fluorescence. A, Dorsal view. B, Ventral view. Scale bars: 500 μm.

FIGURE 3. Details of Murcybolus longiantennus gen. et sp. nov., female, holotype, NIGP173914, under confocal microscopy, with depth colour-coding in A–F. A, Head and prothorax, dorsal view. B, Elytral base. C, elytral apex, showing the interrupted costae 2 and 3 (arrowheads). D, Head and prothorax, ventral view. E, Legs, ventral view. F, Abdominal apex, ventral view. G–H, Same as A–B. I, Anterior portion of abdomen, ventral view. J–L, Same as D–F. Abbreviations: a1–4, antennomeres 1–4; el, elytron; ey, compound eye; lb, labrum; lbp, labial palp; ml, mala; md, mandible; mstb, mesotibia; msts, mesotarsus; mtf, metafemur; mttb, metatibia; mttc, metatrochanter; mxp, maxillary palp; pc, procoxa; pf, profemur; pn, pronotum; ps, prosternum; ptb, protibia; sc, scutellum; v1–7; ventrites 1–7. Scale bars: 200 μm.