Platymessa Mello-Leitão, 1941

Medrano, Miguel & Kury, Adriano B., 2016, Characterization of Platymessa with redescription of the type species and a new generic synonymy (Arachnida, Opiliones, Cosmetidae), Zootaxa 4085 (1), pp. 52-62 : 54-57

Platymessa Mello-Leitão, 1941

Platymessa Mello-Leitão, 1941: 167 ; Roewer 1963: 52; Kury 2003: 81 (type species Platymessa H-inscripta Mello-Leitão, 1941, by original designation).

Platimessa [incorrect original spelling]: Mello-Leitão 1941: 167.

Brachylibitia Mello-Leitão, 1941: 166 ; Kury 2003: 38 [junior subjective synonym of Cynorta C.L. Koch, 1839 by Goodnight & Goodnight (1953: 38); synonymy disclaimed by Kury (2003: 38); type species: Brachylibitia ectroxantha Mello-Leitão, 1941 ; by original designation]. SYN. NOV.

Etymology. Brachylibitia : from Greek βραχύς (short) + pre-existing generic name Libitia . Gender feminine. Platymessa : from Greek πλατύ- (flattened) + pre-existing generic name Messa . Gender feminine.

Diagnosis. Outline of the dorsal scutum beta-shaped in males and almost alpha-shaped in females ( Figs 1 , 7 ); coda longer in females ( Fig. 9 ); scutal area V with two small paramedian granules; yellowish white color markings of scutum as a ladder mask (a pair of divergent bars connected by parallel thinner blots over scutal grooves) over dark brown background, thinner blots sometimes dissociated. Dorso-apical apophysis of coxa IV as a blunt spine ( Figs 1 , 7 ). Chelicerae monomorphic, weak, with marginal rows of acuminate tubercles of varied size on posterior border. Groin warts present, larger in female. Legs short and strong, femur III and IV slightly arched and with five longitudinal rows of small tubercles; basitarsomeres of leg I of male thicker than distitarsomeres but not swollen; cheliceral sockets shallow with well-marked lateral triangular projections.

Taxonomic background of Brachylibitia and Platymessa . Mello-Leitão (1941) described the genera Brachylibitia and Platymessa with three species from Colombia: B. ectroxantha , P. h-inscriptum and P. nigrolimbata . These new genera were based on the armature of the scutal areas and the count of tarsomeres of the leg I (see Discussion section). Roewer (1963) described a third species of Platymessa , P. transversalis from Peru also based only on those features.

Included species. Platymessa ectroxantha ( Mello-Leitão, 1941) comb. nov., species inquirenda and Platymessa h-inscriptum Mello-Leitão, 1941 (type species).

Figures

FIGURES 1 – 6. Platymessa h-inscriptum Mello-Leitão, 1941: 1. Male holotype (MNRJ 282), habitus, dorsal view. 2. Same, lateral view. 3. Male (ICN-AO 1186) habitus, frontal view. 4. Same, posterior view. 5. Male (MNRJ 58) proximal part of coxa IV showing groin warts, dorsal view. 6. Female (MNRJ 463) proximal part of coxa IV showing groin warts (or clavus inguinis = ci), dorsal view. Scale bars = 1 mm.

FIGURES 7 – 18. Platymessa h-inscriptum Mello-Leitão, 1941: 7. Male holotype (MNRJ 282) habitus, dorsal view 8. Schematic outline of dorsal scutum of male. 9. Schematic outline of dorsal scutum of female. 10 – 18. Variation of the pattern of spots in dorsal scutum: (10,11,12,15,16) ♀♀ ICN-AO 1186, (13) ♂ ICN-AO 1186, (14,17) ♀♀ ICN-AO 1384, (18) ♂ ICN-AO 1384. Scale bar = 1 mm.