Eourocerus Archibald & Rasnitsyn, 2022

Archibald, S. B. & Rasnitsyn, A. P., 2022, The early Eocene Eourocerus anguliterreus gen. et sp. nov. (Hymenoptera, Siricidae) from Republic, Washington, Zootaxa 5105 (2), pp. 289-295 : 290

Eourocerus Archibald & Rasnitsyn , new genus

Figure 1 , 2B

Diagnosis. The forewing of Eourocerus is most like that of Urocerus Geoffroy, 1785 (see below), but is most easily distinguished by shape: length/width estimated ca. 3.0 [ Urocerus 3.2]; apex broadly rounded almost as in Sirotremex Smith, 1988 [ Urocerus , angularly rounded] ( Fig. 2 ). It may also be distinguished from those of other genera of Siricinae by the combination of: 2r-rs basal to 2r-m; 1r-rs extremely short, almost its width long; 1r-m absent, replaced with Rs+M; 2r-m and 3r-m present, 2r-m basal to 2mcu; Cu1 absent; crossvein cu-a more than half its length distal to M+Cu.

Type species. Eourocerus anguliterreus .

Description. As for its only species.

Etymology. The genus name is formed from “Eocene” and “ Urocerus ”. Gender, masculine.

Range and age. Ypresian Tom Thumb Tuff Member of the Klondike Mountain Formation at Republic, Washington, USA.

Figures

FIGURE 1. Holotype Eourocerus anguliterreus gen. et sp. nov., SRUI-99-97-08A, B. A, photograph of part, SRUI-99-97- 08A; B, drawing from part and counterpart. Both to scale, 5 mm. Cell names in italics, vein names in Roman font.

FIGURE 2. Comparison of forewing shapes of A, Urocerus albicornis (Fabricius, 1781) drawn from Schiff et al. (2012) figure B1.71, and; B, Eourocerus anguliterreus. For shape comparison, they are to different scales, aligned to the branching of M+Cu and 3r-m.