Conosphaerion concolor Click here for a larger view

Diagnosis.--Key characters: Ommatidial size coarse (Fig. 39b); procoxal process expanded apically (Fig. 18); mesal antennal spines present (Figs. 8b, 9b); pronotum with impunctate regions present; femoral carinae absent; procoxal cavities closed laterally (Fig. 24); femoral apices rounded (Fig. 26); femora clavate (Fig. 37b); elytra not metallic and without dense pubescence; posterior procoxal cavities open (Fig. 18); pronotum without transverse ridges; mesotibial carinae present (Fig. 22); pronotum and head without dense yellow or white pubescence; antennomeres carinate but not sulcate (Fig. 45b, c); spine of antennomere three acute (Fig. 45b); antennomere shape linear, not expanded at apices (Fig. 22); lateral pronotal tubercles present (Fig. 12e, f); elytral apices truncate (Fig. 41b-d); elytra and pronotum without dense vestiture of short pubescence; antennomere three of males about two-thirds length of pronotum (Fig. 46b); pronotal punctation confluent and alveolate (Fig. 12b), but irregularly-sized; metepisternal notch without protuberance. Length: 7-15 mm.

Distribution and Diversity.--México, Panamá. Two species.

Discussion.--Conosphaerion is a very basal elaphidionine based on the results of the implied weight phylogenetic analysis. Its relationship to other elaphidionine genera is equivocal. In most of the shortest, fittest trees obtained, it fell within a clade containing Anopliomorpha and Clausirion (Figs. 51, 53-55). In one of the shortest, fittest trees (Fig. 52) it was the sister taxon to the rest of Elaphidionini.

The acute, broad-based lateral pronotal tubercles and alveolate-punctate pronotum characterize Conosphaerion well. It occurs near Sphaerion in the key, but Sphaerion lacks the alveolate punctures on the pronotum and has (at least in the examined species) a small protuberance from the metepisternum near the region of the notch.