Megapsyrassa xestiodes Click here for a larger view

Diagnosis.--Key characters: Ommatidial size coarse (Fig. 39b); prosternal process greatly expanded apically (Fig. 27); mesal antennal spines present (Figs. 8b, 9b); pronotum with impunctate regions; femoral carinae absent; procoxal cavities closed laterally (Fig. 24); profemoral apices rounded (Fig. 26); mesal and lateral meso- and metafemoral apices usually dentiform (as in Fig. 25b); posterior procoxal cavities closed (Fig. 27); mesocoxal cavities open laterally (Fig. 7); lateral projections into mesocoxae from mesosternum present (Fig. 21); elytra typically sinuate above metepisternum, concealing it in part below the metepisternal keel (Fig. 32); pronotum nearly impunctate and glabrous and much longer than wide (Fig. 41c); pronotum without calli; antennae with multiple carinae (Fig. 45c); tibiae sinuate; tibiae carinate (Fig. 22); profemoral shape clavate (Fig. 37b); mesofemora and metafemora gradually enlarged or linear (Fig. 37c, d); elytral spines usually strong laterally and suturally (as in Fig. 41a). Length: 11-23 mm.

Distribution.--México to Panamá. Eight species.

Discussion.--Megapsyrassa is shown to be closely related to Aneflus and Psyrassaforma. The analysis revealed a sister-group relationship to Aneflomorpha tenuis, but as I have discussed, this species of Aneflomorpha may be a highly derived member of the genus and not necessarily a good exemplar.

Megapsyrassa has many key characters of Aposphaerion, but has dentiform metafemoral apices mesally (Aposphaerion has them rounded), open mesocoxal cavities laterally (closed in Aposphaerion), and elytra concealing part of the metepisternum below the keel (exposed normally in Aposphaerion). Clausirion, which occurs in the key near Megapsyrassa, lacks the mesocoxal projections from mesosternum and has pronotum about as wide as long. Psyrassa generally are smaller, have a postero-lateral pronotal constriction, have linear antennae (usually slightly expanded apically in Megapsyrassa) and have the metepisternum completely exposed below the keel.