Burmoptarthrus storozhenkoi, Legalov, 2025

Legalov, Andrei A., 2025, First record of the subfamily Brenthorrhininae (Coleoptera, Nemonychidae) in Cretaceous Kachin amber, Zootaxa 5715 (1), pp. 225-235 : 226-231

Burmoptarthrus storozhenkoi sp. nov.

urn:lsid:zoobank.org:act:

( Figs 1–4 )

Material. Holotype, female, MA2024/1, Burmese amber, Myanmar, Cenomanian, late Cretaceous . Paratype, male, MA2018/18, Burmese amber, Myanmar, Cenomanian, late Cretaceous . The paratype is damaged. Only the front part of its body is well preserved .

Description. Body black-brown, moderately sclerotized, subflattened dorsally. Integument covered with dense semierect pale hairs.

MALE. Head capsule strongly constricted behind eyes. Labrum well developed, separated from rostrum, subrectangular. Maxillary palpi 4-segmented, flexible. Rostrum elongated, weakly curved, densely punctate, slightly thickened at apex, about 6.4 times as long as wide at apex, about 7.4 times as long as wide at mid length, about 6.7 times as long as wide at base, 1.2 times as long as pronotum. Dorsal surface of rostrum without carinae. Ventral surface of rostrum with two weak carinae. Antennae long, thin, non-geniculate, inserted laterally in basal part of rostrum, with quite long pale setae. Place of antennal insertion not extended. Distance from rostrum apex to antennal insertion 6.7 times as long as distance from rostrum base to antennal insertion. Antennomeres subconical. Antennomere 1, about 2.1 times as long as wide at mid length. Antennomere 2, about 1.3 times as long as wide at apex, about 0.5 times as long as and about 0.8 times as narrow as antennomere 1. Antennomeres 2-6 subequal. Antennomere 3, about 2.2 times as long as wide at apex, about 1.4 times as long as and about 0.8 times as narrow as antennomere 2. Antennomere 7, 1.4 times as long as wide at apex, 0.7 times as long as and slightly wider than antennomere 6. Antennomere 8, about 1.5 times as long as wide at apex, about 1.2 times as long as and 1.1 times as wide as antennomere 7. Antennal club not compact, its three segments free. Antennomere 9, about 1.7 times as long as wide at apex, about 1.2 times as long as and about 1.1 times as wide as antennomere 8. Antennomere 10, 1.5 times as long as wide at apex, 1.2 times as long as and about 1.3 times as wide as antennomere 9. Antennomere 11, 2.8 times as long as wide at base, about 1.2 times as long as and about 0.6 times as narrow as antennomere 10. Eyes elliptical, distinctly protruding from head. Temples short, about 0.8 times as long as eye length. Forehead wide, flattened, densely punctate. Pronotum bell-shaped, with arcuate sides. Disc weakly flattened, coarsely punctate and granulated. Greatest width at mid length. Lateral margins of pronotum granulated. Scutellum large, subtrapezoid, about 0.7 times as long as wide. Elytra with slightly smoothed humeri. Scutellar striole distinct. Precoxal portion of prosternum about 0.8 times as long as procoxal cavity length. Postcoxal portion of prosternum about of same length to procoxal cavity length and about 1.2 times as long as precoxal portion. Procoxal cavities located near middle of prosternum, rounded and contiguous. Mesocoxal cavities rounded, narrowly separated. Legs long. Trochanters oblique. Femora quite slender, slightly incrassating subapically, covered with tubercles. Tibiae almost straight, widened at apex, covered with tubercles, without mucro; with two apical spurs. Tarsi wide, pseudoquadrisegmented. Tarsomeres 1–3 with pulvilli on lower surface. Tarsomere 1 wide-conical. Tarsomeres 2 and 3 conical-bilobed. Tarsomere 5 long and narrow. Claws free, strongly divergent, without teeth at base. Protarsi: tarsomere 1 about, 0.4 times as long as wide at apex; tarsomere 2, about 0.4 times as long as wide at apex, slightly shorter and narrower than tarsomere 1; tarsomere 3, about 0.9 times as long as wide at apex, 2.6 times as long as and about 1.3 times as wide as tarsomere 2; tarsomere 5, about 3.7 times as long as wide at apex, about 1.7 times as long as and about 0.4 times as narrow as tarsomere 3. Head and pronorum length 2.5 mm; rostrum length 2.0 mm.

FEMALE. Labrum about 0.5 times as long as wide. Mandibles small, not exodontous. Rostrum 5.0 times as long as wide at apex, about 8.3 times as long as wide at mid length, about 7.1 times as long as wide at base, 1.2 times as long as pronotum. Antennae extend beyond middle of pronotum, inserted in basal part of rostrum. Distance from rostrum apex to antennal insertion 5.6 times as long as distance from rostrum base to antennal insertion. Antennomere 1, 1.8 times as long as wide at mid length. Antennomere 2, 1.5 times as long as wide at apex, about 0.7 times as long as and 0.8 times as narrow as antennomere 1. Antennomere 3, about 3.3 times as long as wide at apex, about 2.2 times as long as and of same width to antennomere 2. Antennomere 4, about 1.3 times as long as wide at apex, about 0.5 times as long as and slightly wider than antennomere 3. Antennomere 5, about 1.3 times as long as wide at apex, about 0.8 times as long as and slightly narrower than antennomere 4. Antennomere 6, about 1.6 times as long as wide at apex, slightly shorter and wider than antennomere 5. Antennomere 7, about 1.6 times as long as wide at apex, slightly longer and wider than antennomere 6. Antennomere 8, about 1.1 times as long as wide at apex, of same length and about 1.4 times as wide as antennomere 7. Antennal club not compact, its three segments free. Antennomere 9, about 1.3 times as long as wide at apex, about 1.3 times as long as and about 1.1 times as wide as antennomere 8. Antennomere 10, 1.5 times as long as wide at apex, of same length and slightly wider than antennomere 9. Antennomere 11, about 3.1 times as long as wide at base, about 1.6 times as long as and about 0.8 times as narrow as antennomere 10. Eyes distinctly protruding from head. Temples about 0.4 times as long as eye length. Forehead about 1.9 times as wide as rostrum base width, flattened, densely punctate. Pronotum bell-shaped, with arcuate sides, about 2.0 times as long as wide at apex, slightly longer than wide at mid length, about 1.2 times as long as wide at base. Disc weakly flattened, coarsely punctate and granulated. Greatest width at mid length. Lateral margins of pronotum granulated. Scutellum 0.7 times as long as wide. Elytra quite wide, about 1.6 times as long as wide at base and at apical fourth, about 1.3 times as long as wide at mid length, about 2.0 times as long as pronotum; weakly punctostriate, with slightly smoothed humeri and distinct wide epipleura. Greatest width behind middle. Disc coarsely punctate and granulated. Striae indistinct. Scutellar striole distinct. Prosternum, covered with tubercles. Precoxal portion of prosternum about 0.8 times as long as procoxal cavity length. Postcoxal portion of prosternum about of same length to procoxal cavity length and about 1.6 times as long as precoxal portion. Procoxal cavities located near middle of prosternum, rounded and contiguous. Mesocoxal cavities rounded, narrowly separated. Metacoxal cavities transverse. Metaventrite convex, long, about 2.2 times as long as metacoxal cavity. Metanepisterna about 5.7 times as long as wide at mid length, finely punctate. Abdomen weakly convex. Ventrites free. Ventrite 1, about 1.5 times as long as metacoxal cavity. Ventrite 2, slightly shorter than ventrite 1. Femora covered with tubercles, without teeth. Tibiae almost straight, widened at apex, covered with tubercles, without mucro; with two apical spurs. Tarsi wide, pseudoquadrisegmented. Tarsomeres 1–3 with pulvilli on lower surface. Tarsomere 1 wide-conical. Tarsomeres 2 and 3 conical- bilobed. Tarsomere 5 long and narrow. Claws free, strongly divergent, without teeth at base. Body length without rostrum 6.0 mm; rostrum length 1.9 mm.

Etymology. The species is named in honour of Dr. Sergei Yu. Storozhenko (Vladivostok, Russia).

Remarks. In females, the rostrum is more strongly expanded at the apex (5.0 times as long as wide at apex) and narrower in the middle (about 8.3 times as long as wide at mid length), whereas in males, it is less expanded at the apex (6.4 times as long as wide at apex) and wider in the middle (about 7.4 times as long as wide at mid length).

Figures

FIGURE 1. Burmoptarthrus storozhenkoi gen. et sp. nov., holotype, female, habitus: A—dorsal view; B—ventral view. Scale bar = 2.0 mm.

FIGURE 2. Burmoptarthrus storozhenkoi gen. et sp. nov., holotype, female, body outline: A—dorsal view; B—ventral view. Scale bar = 2.0 mm.

FIGURE 3. Burmoptarthrus storozhenkoi gen. et sp. nov., paratype, male, habitus: A—dorsal view; B—ventral view. Scale bar = 1.0 mm.

FIGURE 4. Burmoptarthrus storozhenkoi gen. et sp. nov., paratype, male, body outline, ventral view. Scale bar = 1.0 mm.