Eugonus angustus, Poinar & Legalov, 2016

Poinar, George & Legalov, Andrei A., 2016, New Anthribidae (Coleoptera: Curculionoidea) in Dominican and Mexican ambers, Palaeontologia Electronica 148 (1), pp. 1-38 : 7-9

Eugonus angustus sp. nov.

Figure 4

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Holotype. Deposited in the PACO (accession # C-112).

Description. Length body, 6.3 mm; length rostrum, 0.8 mm. Body black with a covering of quite distinct, brownish, appressed setae. Rostrum wide and short, 0.5 times as long as pronotum, flat, without dorsal median carina; antennal scrobes almost sulciform, dorso-lateral, contiguous with eyes; forehead wide, convex, punctate; eyes large, almost rounded, distinctly convex, 1.2 times longer than wide; vertex weakly convex, densely punctate; temples quite long; antennae inserted at base of rostrum, quite long, not reaching middle of pronotum; antennal club not compact. Pronotum long bell-shaped; 1.7 times longer than wide at apex, 1.3 times longer than wide in middle, 1.6 times longer than wide at base, with complete lateral carina reaching front margin of pronotum; disk weakly convex, densely punctate; weakly transverse dorsal pronotal carina basal; scutellum trapezoidal. Elytra cylindrical, elongate and weakly convex, 2.5 times longer than wide at base and in middle, 3.1 times longer than wide at apical fourth, 1.9 times as long as pronotum, without clusters of setae; greatest width in middle; humeri weakly flattened; striae regular and distinct; strial punctures oval, dense; elytral intervals convex, wide, 3.0–4.0 times as wide as striae; apices of elytra not rounded; pygidium not concealed. Thorax punctate; precoxal portion of prosternum quite elongate, 1.9 times as long as procoxal cavities, 2.5 times as long as postcoxal portion; postcoxal portion 0.8 times as long as procoxal cavities; procoxal cavities narrowly separated; mesocoxal cavities widely separated; metaventrite densely punctate, metanepisternum narrow. Abdomen convex; first ventrite 1.1 times as long as length of metacoxal cavity; second ventrite 0.6 times as long as length of first ventrite; third ventrite 0.9 times as long as length of second ventrite; fourth ventrite equal in length to length of third ventrite; fifth ventrite 1.5 times as long as length of fourth ventrite. Legs long; pro- and mesocoxae round; metacoxae transverse; femora clavate, without teeth; trochanters obconical; profemora 3.4 times longer than wide; mesofemora 3.5 times longer than wide; metafemora 2.4 times longer than wide; tibiae flattened, almost straight; protibiae 6.0 times longer than wide in middle; mesotibiae 6.0 times longer than wide in middle; metatibiae 6.6 times longer than wide in middle; tarsi long, black; first to third tarsomeres conical; second tarsomere embracing third tarsomere laterally; fifth tarsomere elongate; tarsomeres with pulvilli on underside; tarsal claws free, large, distinct diverging, with basal teeth.

Type locality. Amber mine in the Cordillera Septentrional of the northern portion of the Dominican Republic.

Etymology. The specific epithet is taken from the Latin “angustus ” equals narrow, in reference to the body form of the fossil.

Comparison. The new species is similar to E. subcylindricus Fahraeus, 1839 from Central and South America but differs by the small, and narrow body size, elongate elytra and pronotum, convex elytral intervals, stronger convex eyes and densely punctate metaventrite.

Figures

FIGURE 4. Holotype of Eugonus angustus sp. nov. PACO no. C-112 in Dominican amber. 1, dorsal view, scale bar equals 1.2 mm; 2, ventral view, scale bar equals 1.3 mm; and 3, lateral view, scale bar equals 1.4 mm.