Electropteron Kazantsev, 2020

Kazantsev, S. V., 2020, First fossil representative of the net-winged beetles genus Plateros Bourgeois, 1879 (Insecta: Coleoptera: Lycidae) from Mexican amber, with redescription of Electropteron avus gen. n., sp. n. from Dominican amber and a note on the time of origin of the family, Russian Entomological Journal 29 (4), pp. 377-387 : 381-382

Electropteron Kazantsev , gen.n.

Type species: Electropteron avus Kazantsev , sp.n.

DESCRIPTION. Adult male. Alate, slender, elongate ( Figs 7–8 ). Head subquadrate, slightly narrowed behind eyes. Fastigium right-angled. Eyes relatively small, spherical.Maxillary palps slender, with ultimate palpomere pointed distally. Gula prominent. Antennal prominence conspicuous, antennal sockets approximate. Antenna 11–segmented, moderately long, slightly widening distally; antennomeres 4–11 flattened, antennomeres 2 and 3 short, transverse, subequal in length; pubescence on antennomeres 4–11 relatively short and erect ( Figs 7–9 ).

Pronotum small, ca. 6 times shorter than elytra, transverse, trapezoidal, with obscure median impression in posterior third; posterior angles produced laterally ( Fig. 7 ). Prosternum short, V-shaped ( Figs 8 , 10 ). Thoracic spiracles small, not projecting beyond coxae. Mesoventrite transverse, short. Mesonotum with rather prominent, elongate scutellum ( Fig. 7 ).

Elytra long, narrowing and dehiscent distally, covering abdomen, except genital capsule, with two noticeable primary costae (presumably, costae 2 and 4); interstices irregularly areolate; short and erect elytral pubescence uniform ( Fig. 7 ). Metaventrite transverse, with acute posterior angles; discrimen complete, attaining to mesosternum.

Pro- and mesocoxae elongate; metacoxae approximate; angle between metacoxae ca. 90º. Legs slender; trochanters elongate, but considerably shorter than femurs, cylindrical, connected to femora distally; femurs and tibiae flattened, tibiae straight, widened distally; tarsomeres 1–4 narrow, without plantar pads; all claws simple. Ultimate sternite and tergite elongate, pointed at apex ( Figs 7–8 , 11 ).

Female. Unknown.

ETYMOLOGY. The name of the genus is derived from ‘electron’ and ‘pteron’, the Greek for ‘amber’ and ‘wing’. Gender neuter.

DIAGNOSIS. Electropteron gen.n. appears to be related to the extant genus Tainopteron Kazantsev, 2009 , from Puerto Rico [ Kazantsev, 2009], distinguishable by the flattened and distally slightly widening antennomeres 4–11, less transverse pronotum and more elongate elytra completely covering the folded wings ( Fig. 7 ). The new genus is different from Leptolycus Leng et Mutchler, 1922 , another Greater Antillean extant endemic [ Kazantsev, 2009], by the flattened antennomeres 4–11 with even edges and short pubescence, transverse pronotum with explanate sides and short V-shaped prosternum ( Figs 7–8 , 10 ). On the other hand, Electropteron gen.n. is somewhat similar to Ceratoprion Gorham, 1884 , distributed in the highlands of Central America and the Ands south to Ecuador, differing by the non-serrate antennomeres 4–11 and their erect pubescence and by the absence of the median longitudinal pronotal carina.

REMARKS. Electropteron avus gen.n., sp.n., which is evidently close to some of the extant Leptolycini from Hispaniola and Puerto Rico, is tentatively attributed to the same tribe, although the tribe itself with the unusually wide range of morphologies of its members [e.g., Kazantsev, 2009; 2017] may prove to represent several independent lineages. The tribe Leptolycini is confined to Central America, Greater Antilles, and mostly northern part of South America. The discovery of a representative of this group in the ca. 20 myo Dominican amber, actually in the area of the current distribution of its close relatives, gives further clues for the reconstruction of the history and phylogenetics of the family.

Figures

Figs 7–8. General view of Electropteron avus gen.n., sp.n., holotype male: 7 — dorsally; 8 — ventrally. Рис. 7–8. ОбЩий вид Electropteron avus gen.n., sp.n., голотип, самец: 7 — сверху; 8 — сниЗу.

Figs 9–11. Details of Electropteron avus gen.n., sp.n., holotype male: 9 — antenna; 10 — prosternum; 11 — terminal abdominal segments ventrally. Scale: 0.5 mm. Рис. 9–11. Детали строениЯ Electropteron avus gen.n., sp.n., голотип, самец: 9 — антенна; 10 — переднегрудь; 11 — вершинные сегменты брюшка, сниЗу. МасштабнаЯ линейка: 0.5 мм.