Neusiokia appalachiensis Muona, 2022

Muona, Jyrki, 2022, New fossil false click-beetles from the Americas (Coleoptera: Eucnemidae), Insecta Mundi 2022 (912), pp. 1-11 : 3-6

Neusiokia appalachiensis Muona , new species

Figures 1–5 .

Etymology. Named after the eastern Cretaceous part of the North American continent.

Holotype. Embedded in a triangular North Carolina resin piece, 17 × 10 × 9 mm, sex unknown. Found from locality 34 in Goldsboro, a Cretaceous Black Creek Formation exposure along the Neuse River ( Carter et al. 1988).

Diagnosis. Characterized by the enlarged f7–f 9 in combination with two protibial spurs and small size.

Description. Length 4.5 mm. Elateroidea synapomorphy: pro-mesocoxal clicking mechanism present.

Eucnemidae synapomorphies: pedicel attached subapically to scape, labrum hidden and sutural striae with excretory punctures apically. Head rounded, very densely punctate, eyes medium sized, frontoclypeal region wide, about 1.5 times as wide apically as between antennal sockets, apical margin straight with caudally projecting lateral apices, mandibles elongated with simple apex ( Fig. 5 ). Pronotum about as wide as long, sides evenly and strongly narrowing craniad, with rounded hind angles, lateral and frontal margins simple, scutellum wider than long, bluntly pointed caudad, parallel-sided on basal half, elytra with rounded sides, striae distinct, sutural ones strong apically with excretory punctures, interstices nearly flat, moderately densely punctate ( Fig. 2 ). Antennal fairly short, f9 reaching pronotal hind angles, scape elongate, nearly as long as pedicel and f1–f2 combined, f2–f6 twice as long as wide, apically expanded, f7–f9 forming loose, fattened club ( Fig. 4 , 5 ).

Hypomera simple, smooth, widely and shallowly grooved, delimited by notosternal suture medially and pronotal ridge laterally, prosternal peg wide, short, prosternum narrow, metasternum densely punctate, without mesocoxal lines. Metacoxal plates densely punctate, elongate, widest close to midline, here about twice as wide as on sides ( Fig. 1 ). Legs long, femora stout, fairly short, meso- and metatibiae long, strongly built, with well-developed spine-combs, meso- and metatarsi shorter than tibiae, protibia short, powerful, apically expanded, apex with two spurs, dorsal apical spur split in two ( Fig. 3 ), first protarsomere without sex-comb, fifth protarsomere exceptionally long ( Fig. 4 ), all tarsomeres 4 simple, claws simple ( Fig. 1 , 3 , 4 ). Abdominal ventrites connate, densely punctate ( Fig. 1 ).

Remarks. Neusiokia appalachiensis challenges the present classification, partly in the same manner as Erdaia bisipnulosa did ( Muona 2021). On the basis of the presently accepted synapomorphies, they both appear to belong in the subfamily Palaeoxeninae . As a new analysis is needed to clarify this question, I have chosen to place Neusiokia provisionally in Orodotini .

Family Eucnemidae Eschscholtz, 1829

Subfamily Macraulacinae Fleutiaux, 1922

Tribe Macraulacini Fleutiaux, 1922

Figures

Figure 1. Neusiokia appalachiensis n. sp., holotype, ventrolateral view.

Figure 2. Neusiokia appalachiensis n. sp., holotype, dorsal view.

Figure 3. Neusiokia appalachiensis n. sp., holotype, ventral view of tips of protibiae and protarsi. Left arrow points at the divided protibial spur, right arrow points at the second protibial spur.

Figure 4. Neusiokia appalachiensis n. sp., holotype, ventral view of head, pro- and mesothorax.

Figure 5. Neusiokia appalachiensis n. sp., holotype, ventrolateral view of pronotum and head.