Igneonasus, Legalov & Poschmann, 2020

Legalov, Andrei A. & Poschmann, Markus J., 2020, New genus of the tribe Ceutorhynchini (Coleoptera: Curculionidae) from the late Oligocene of Enspel, southwestern Germany, with a remark on the role of weevils in the ancient food web, Fossil Record 23 (2), pp. 197-204 : 198-199

Genus Igneonasus gen. nov.

urn:lsid:zoobank.org:act:CE2FAC7D-C476-464A-

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Type species

I. rudolphi sp. nov., herein designated.

Etymology

The generic name is derived from the Latin igneo for fire, with respect to the volcanic origin and destruction of the paleolake Enspel, and nasus for nose. Gender masculine.

Diagnosis

Large beetle; body black, strongly chitinized; rostrum longer than pronotum, rather thick, curved; antennal scrobes lateral; forehead flattened; antennae inserted in apical third of rostrum; anterior margin of pronotum not raised; pronotum with longitudinal median sulcus; sides without tubercles; elytra plump with convex humeri; striae regular; interstriae very wide; prosternum and mesoventrite with rostral channel; postocular lobes present; precoxal portion of prosternum elongated; mesepimeron strongly ascending; abdomen convex ventrally; ventrites 1 and 2 elongated; ventrites 3 and 4 short; pygidium convex, exposed beyond elytra; legs long; procoxae subconical; femora weakly clavate, without teeth; tibiae almost straight, without uncus; tarsomeres 1 and 2 conical.

Comparison

The new genus can be compared with the genus Stenocarus C.G. Thomson, 1859 because of the rather thick rostrum and mesoventrite with the rostral channel but differs in the non-raised anterior margin of the pronotum, the pronotum without tubercles on the sides, and the femur without teeth. Its large body size (7.8 mm) makes the new genus the largest known Ceutorhynchitae . Previously, the largest were species of the genus Mogulones Reitter, 1916 with a maximum length (6.4 mm) and Mononychus Germar, 1823 with 6.0 mm ( Arnoldi et al., 1965; Gültekin and Colonnelli, 2006). The new genus differs from the genus Mogulones in the non-raised anterior margin of the pronotum, rather thick rostrum, mesoventrite with the rostral channel, and the femur without teeth. Mononychus differs from other Ceutorhynchitae genera in the one tarsal claw ( Colonnelli, 2004; Legalov, 2018), but the structure of the claws in the new genus is not known. The new genus is distinguished from this genus in the rather thick rostrum with subapically inserted antennae and mesoventrite with rostral channel. The genus Phrydiuchus Gozis, 1885 also has a rather thick rostrum. The new genus differs from Phrydiuchus in a rostrum narrower than profemora, non-raised anterior margin of the pronotum, pronotum without lateral tubercles, mesoventrite with rostral chan-

A. A. Legalov and M. J. Poschmann: New genus of the tribe Ceutorhynchini ( Coleoptera : Curculionidae ) 199

nel and large body size. An interesting character is the non-raised anterior margin of the pronotum, which is present in some genera ( Datonychus Wagner, 1944 , Tapinotus Schoenherr, 1826 ) with quite large species. The new genus differs from Datonychus in the thicker rostrum, mesoventrite with rostral channel, the pronotum without tubercles, femora without teeth, and larger body size. It differs from Tapinotus of the tribe Scleropterini in the thinner rostrum with subapical inserted antennae, wide pronotum, non-elongated elytra, mesoventrite with rostral channel, and femora without teeth.

Remarks

The strongly ascending mesepimeron suggests placement in the subfamily Conoderinae . Placement of the fossil genus in the subtribe Ceutorhynchitae is based on the rounded plump body, unarmed tibiae, exposed pygidium, and long ventrites 1 and 2, where ventrite 1 is longer than ventrite 2. The new genus belongs to the tribe Ceutorhynchini based on the long precoxal portion of the prosternum, a distinctly long rostrum, which is narrower than width of the profemur, and metafemora not thicker than other femora.