Pantonyssus nigriceps Click here for a larger view

Diagnosis.--Key characters: Ommatidial size coarse (Fig. 39b); prosternal process not planar, expanded at apex (Fig. 18); mesal antennal spines present (Figs. 8b, 9b); pronotal impunctate regions present; pronotum without longitudinal rugosities or large, uniformly-sized punctures; femoral carinae absent; lateral procoxal cavities closed (Fig. 24); profemoral apices rounded (Fig. 26); lateral meso- and metafemoral apices strongly spinose, spines longer than those of antennomere three (Fig. 25a); mesal meso- and metafemoral apices dentiform to weakly spinose (Fig. 25b); posterior procoxal cavities open (Fig. 18); tibial carinae present (Fig. 22); apicolateral spine of elytra very strong; apicosutural spine weak; apices of elytra and femora, and head black in most species. Length: 9-12 mm.

Distribution and Diversity.--Bolivia, Brazil, Colómbia, French Guyana, Panamá. Seven species.

Discussion.--Based on the implied weighting phylogenetic analysis, Pantonyssus fell as the sister group to Parastizocera. However, both taxa are among a large, unresolved polytomy (Fig. 50). Further character analysis and inclusion of more taxa are needed to fully understand the relationships within this level of the cladogram.

Pantonyssus differs from Parastizocera in lacking lateral pronotal tubercles (rounded tubercles present in Parastizocera) and having antennomere three two-thirds length of pronotum (length of pronotum in most specimens of Parastizocera). Pantonyssus differs from Stizocera (and also Parastizocera) in having spines of the meso- and metafemora very long and acute (short and broad in Stizocera and Parastizocera).