Mecyclothorax acutangulus Perrault, 1988: 241

Liebherr, James K., 2013, The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Tahiti, Society Islands, ZooKeys 322, pp. 1-170 : 77

64. Mecyclothorax acutangulus Perrault, 1988: 241

Identification.

This species shares the expanded pronotal and elytral lateral margins of other members of the Mecyclothorax gourvesi group (Fig. 34B), but deviates by the larger body size, standardized body length 6.2 mm. The elytra are broadly extended laterad from the humeri, moreso even than in Mecyclothorax gourvesioides (Fig. 35B), resulting in broadly quadrate elytra. The head surface is glossy, with only small micropunctures - i.e., pore canals - disturbing the smooth surface. An obsolete transverse mesh, sculpticell breadth 3 –4× length, is visible on the pronotal disc, best seen in areas partially in shadow from illumination due to the curvature of the surface; micropunctures also visible across the pronotal surface. The discal elytral intervals are covered with elongate transverse microsculpture consisting of a mixture of transverse sculpticells, breadth 2 –4× length, and transverse lines. The male aedeagal median lobe is broadly expanded both dorsally and ventrally forming a spoon-shaped apex with a broadly convex apical face (Fig. 36B), a configuration that exaggerates the apical expansion of the median lobe in males of Mecyclothorax gourvesi (Figs 36 E–I). The setal formula 2122 is shared with both Mecyclothorax gourvesioides and Mecyclothorax gourvesi .

Distribution and habitat.

This Tahiti Iti representative of the species group is known from specimens collected 900-1100 m elevation on Mont Teatara. A teneral female specimen was obtained by beating Freycinetia plants with rotten leaves, upon some of which lay Cyathea tree fern fronds.