Diagnosis.--Key characters: Ommatidial size coarse (Fig. 39b); prosternal process not planar, slightly expanded at apex (Figs. 18, 27); mesal antennal spines present (Figs. 8b, 9b); pronotum with impunctate regions but no longitudinal rugosities or large confluent punctures; femoral carinae absent; procoxal cavities widely open laterally (Fig. 17); lateral projections from mesosternum into mesocoxae present (Fig. 21); peripheral pronotal calli present but reduced in size; lateral mesocoxal cavities closed (Fig. 6e); antennae sulcate dorsally (Fig. 45a), appearing bicarinate; metafemora pedunculate and clavate (Fig. 37a); long flying hairs scattered on body (Fig. 16); elytra with apex spinose laterally and dentiform suturally; femoral apices with apical projections, but not distinct spines (Fig. 26). Length: 9 mm.

Distribution and Diversity.--Brazil (Matto Grosso). Monotypic.

Discussion.--Since no specimens were available for dissection, this taxon was not represented in the implied weight phylogenetic analysis. I hypothesize that it would fall within the trichotomy related to the Mallocera and allies clade (Fig. 59) and the Sphaerion and allies clade (Fig. 60). The key characters place it very near Parastizocera.

Apoclausirion resembles some Clausirion, but differs in having procoxal cavities open posteriorly (closed in Clausirion). Apoclausirion differs from Stizocera, Pantonyssus, and Nesostizocera in not having spinose metafemoral apices (although there are apical femoral extensions).