Sayrevilleus, GRATSHEV & ZHERIKHIN, 2000

Riedel, Alexander, Rolo, Tomy Dos Santos, Cecilia, Angelica & Kamp, Thomas Van De, 2012, Sayrevilleinae Legalov, a newly recognised subfamily of fossil weevils (Coleoptera, Curculionoidea, Attelabidae) and the use of synchrotron microtomography to examine inclusions in amber, Zoological Journal of the Linnean Society 165 (4), pp. 773-794 : 776

GENUS SAYREVILLEUS GRATSHEV & ZHERIKHIN

Sayrevilleus Gratshev & Zherikhin, 2000: 244 .

Sanyrevilleus Legalov, 2003: 85, 2007: 31 ; 2009: 292; 2010: 93; Bouchard et al., 2011: 560 [incorrect subsequent spelling].

Type species, by original designation: Sayrevilleus grimaldii Gratshev & Zherikhin, 2000 .

Differential diagnosis: Mandible as in Figure 7 , weakly exodont with two blunt teeth. Forehead ( Figs 7, 9 ) with pair of sulci bordering eyes, median subtrapezoid area elevated. Apical edge of pronotum ( Fig. 8 ) continued ventrally to form a rounded extension delimited by marked constriction in front of procoxae. Rostrum distinctly shorter than pronotum (0.86 ¥).

Notes: The genus Sayrevilleus was described by Gratshev & Zherikhin (2000) based on a single inclusion found in Late Cretaceous New Jersey amber. These authors placed it into the tribe Auletini of Rhynchitinae (Attelabidae) based on its simple tarsal claws and an alleged confused elytral punctation. Although simple claws occur in some species of this tribe, this is an exceptional condition for Auletini as the great majority of species have claws with distinct inner teeth. The striation of the elytra of Sayrevilleus could not be assessed because of preservational artefacts. The characters of this fossil largely agree with those of Baltocar : of special significance are the tarsal structure with simple divaricate claws, a long first tarsomere, an apically subtruncate second tarsomere, and the insertion of the onychium in the centre of tarsomere 3 rather than basally as is the case in other Attelabidae and in Caridae . Additionally, the shape and structure of the head are very similar in Sayrevilleus and Baltocar (compare Figs 7–9 with Figs 61–65 ) with a sulcate forehead, a character never occurring in Auletini .

Figures

Figures 1–10. Sayrevilleus grimaldii, holotype: 1, cut amber, in a block of synthetic resin; 2, habitus; left side; 3, habitus; right side; 4, legs; arrows mark simple claws; numbers mark articles of right protarsus; 5, right side of thorax and abdomen; arrow marking side parts of abdominal ventrites; note cracked surface; 6, arrows marking teeth of right mandible; 7–9, volume rendering of synchrotron microtomography of head and thorax; 10, mouthparts: right side; ventrolateral aspect. Abbreviations: Lp, labial palp; Md, mandible; Mxp, maxillary palp; Pr, prementum.

Figures 59–66. Baltocar spp., images created by synchrotron microtomography, 59–64: Baltocar groehni Riedel sp. nov., 65–66: Baltocar hoffeinsorum Riedel sp. nov.; Figures 59, 61, 63 are renderings of 3D models created by manual segmentation; remaining images are volume renderings; 59, 60, oblique frontolateral aspect of mouthparts; 61, 62, dorsal aspect of head; 63, 64, frontal aspect of mouthparts; 65, lateral aspect of head and thorax; 66, frontal aspect of head and thorax.