Holotype male: “ECUADOR: Napo, Yasuní Res.Stn. on mid. Rio Tiputini, 0°40.5'S, 76°24'W. F.I.T.#M1, 7-13 Jul 1999. AKT # 080, C.Carlton & A.Tishechkin” / “LSAM 0012929” / “HOLOTYPE Mecistostethus carltoni Caterino, Tishechkin & Dégallier”; deposited in FMNH.

Length 1.8mm, width 1.4mm; frontal stria interrupted, effaced at middle, not prominently carinate; frons and epistoma with microsculpture; anterior submarginal pronotal stria absent (Fig. 3E); pronotum with <10 discal setae, arranged in submarginal row only (Fig. 3E); lateral pronotal punctures present, but extremely faint; lateral pronotal microsculpture discrete; prosternal striae absent (Fig. 4B); metaventral stria interrupted at middle (Fig. 4B); microsculpture at apex of elytra conspicuous; elytral stria 1 complete, with numerous setae; elytral striae 1 and 2 reaching elytral base; tegmen (Figs 6G–H) widest just distad midpoint, weakly tapering in basal half, basoventral concavity moderately well developed, occupying basal half, with fine median keel; tegmen with moderate ventral swelling near midpoint, only weakly curved toward apex; median lobe only about one-fourth tegmen length.

This species is known only from the type locality, in lowland Amazonian rainforest in eastern Ecuador.

This species is named in honor of Dr. Chris Carlton, director of the Louisiana State Arthropod Museum (LSAM), leader of the field trip on which the type of this species was caught, and AKT’s doctoral advisor.