Nyssicostylus aurivillei Click here for a larger view

Diagnosis.--Key characters: Ommatidial size coarse (Fig. 39b); prosternal process widened, not planar, but not expanded apically; mesal antennal spines present (Figs. 8b, 9b); elytral humeri without tooth at epipleural margin; pronotum with impunctate regions; femoral carinae absent; procoxal cavities widely open laterally (Fig. 17); lateral projections into mesocoxae from mesosternum absent (Fig. 20); femoral apices rounded (Fig. 26); pronotum without distinctive circular callus at base; pronotum usually with acute lateral tubercles (as in Fig. 12f); pronotum punctation sparse (obscured by fine, short vestiture of pubescence); femora clavate and pedunculate (Fig. 37a); tibial carinae present (Fig. 22); elytra without dense patterns of golden and/or silver pubescence; antennae weakly bicarinate dorsally (Fig. 45c); elytral apices weakly bispinose (Fig. 41b-d) Length: 9-11 mm.

Distribution and Diversity.--Brazil, Venezuela. Five species.

Discussion.--Nyssicostylus fell as a sister taxon to the Mallocera and allies clade (Fig. 59). Since many other South American genera could not be included in the analysis, the relationships of these genera cannot be certain.

Nyssicostylus is similar to, and occurs in the key near Rhomboidederes, but differs in having a short vestiture of pubescence on pronotum, coarse non-alveolate punctation on pronotum, unexpanded procoxal process; and weak elytral spines and antennal carinae.