Sibambea rotunda Roewer, 1917: 106

Medrano, Miguel, Kury, Adriano Brilhante & Mendes, Amanda Cruz, 2022, Morphology-based cladistics splinters the century-old dichotomy of the pied harvestmen (Arachnida: Gonyleptoidea: Cosmetidae), Zoological Journal of the Linnean Society 195, pp. 585-672 : 643-644

Sibambea rotunda Roewer, 1917: 106 , fig. 13.

Type data: Holotype: Ecuador. [Chimborazo]: Sibambe [–2.22279°, –78.89538°, 2400 m], 1 ♀ ( SMF RI. examined by photograph).

Non-type material: Ecuador. Napo: [–0.98833°, –77.76667°], 1 ♀ ( QCAZ 125 ) ; Jumandi [–1.02881°, –77.82591°], 1 ♀ ( QCAZ 154 ) ; Yasuni [–0.63333°, –76.5°], 1 ♀ ( QCAZ 153 ) ; Estación Biológica Jatún-Sacha [–1.06597°, –77.61672°], 2 ♀ ( UFMG 9213 ) ; 20 km East of Puerto Napo, Aliñahui [–1.00°, –77.41667°, 450 m], BT & VD Roth leg., 1–14.xii.1994, (post-fire material) 1 ♂ ( CAS AK 103 ) ; [–1.00°, –77.41667°], 1 ♀ ( CAS AK 112 ) . Pastaza: Puyo , [–1.51056°, –78.59528°], 1 ♀ ( QCAZ 129 ) ; 2–8 mi. N. Puyo , [–1.42101°, –78.00358°], 1 ♂ ( CAS AK 003 ) .

Diagnosis: It differs from other Sibambea species by having coxa IV yellowish lateral tubercles ( Fig. 44C ); by having the marginal yellow ring of scutum reticulated and invading gently areas of mesotergum ( Fig. 44A ) and by having the fixed finger of chelicera with keel instead of teeth ( Fig. 45E ).

Distribution: It is known from ecoregions: northwestern Andean montane forest, Northern Andean páramo, Eastern Cordillera real montane forest and Napo moist forest in Ecuador ( Fig. 26 )

Description of male CAS AK 003: Measurements: CL: 1.19, CW: 2.54, AL: 3.47, AW: 4.04, IOD: 0.70, FeIV: 12.42.

Dorsum ( Fig. 44 ). DS delta-type and lenticular in lateral view, without remarkable ornamentation. Anterior edge of dorsal scutum with protoglyphs slightly concave with lateral triangular borders. Ocularium low, with a few granules near the eyes. Mesotergum convex, higher at level of area II, scutal posterior border and free tergites each containing a transverse row of minute granules, anal operculum with scattered minute granules.

Venter. Coxae I– III triangular, transverse to main body axis. Coxae II – IV connected by tubercular bridges. Coxae I– III with a longitudinal row of granules. Coxa IV pentagonal, greatly developed, oriented obliquely, but almost parallel to the body axis. Stigmatic area T-shaped with stigmata large, unconcealed. Free sternites each with a row of granules.

Chelicerae ( Figs 45D, E ). Hand not swollen. Basichelicerite short, with well-marked bulla and uniformly granulated. Posterior margin of the bulla fringed with several tubercles and lateral margin with one isolated tubercle. Movable finger of cheliceral hand without tubercles. Fixed finger with a low keel.

Pedipalps ( Fig. 45F, G ). Elongate trochanter, foliaceus femur; convex dorsally, with a dorsal keel and a ventral row of eight setiferous tubercles. Tibia slightly convex to mesal side, with a ventro marginal row of small setae. Tarsus conical dorsally and ventrally flattened, with scattered dorsal setae and ventrally with three well-marked rows of subequal setae.

Legs ( Fig. 44 ). Long and unarmed legs, femora straight. Coxa IV convex in dorsal view with few apical granules, no clavi inguines, probasal region with a slight incrassation. Pectinate claws in legs II and IV in two rows. Tarsal counts: 6(3), 15(3), 10, 11 ( Roewer, 1917).

Colour (in alcohol, Fig. 44 ). Dorsal scutum and coxae vivid orange (48). Light greenish-yellow (101) ring-like mark bording dorsal scutum and free tergites, entering into carapace in operculum and posterior to eyes and entering in mesotergum in areas II to IV. Area IV and anal operculum, each with two paramedian dots of the same colour. Coxa IV laterally with remarkable nine tubercles of the same colour of DS spots. Podomeres of legs (except coxae) brilliant greenish-yellow (98).

Penis ( Fig. 45A–C ). Ventral plate subrectangular, with triangular apical corners, distal margin concave. Subdistal lateral margin of VP with two pairs of MS-C, large, curved and flattened. Two pairs of MS-D located in apical half of VP, MS-D1 twice longer than MS-D2 and closer to MS-C2, both MS-D straight and conical. One pair of MS-A basally in VP, straight, conical and almost as long as MS-D1 . Two pairs of MS-E in apical portion of lateroventral surface and one pair of MS-B in the basal portion of ventral surface of VP. Ventral surface with two wide lateral regions with microsetae type 3 ( T3 ) near MS-B and MS-E. Glans with dorsal process rounded, wattle going to median part of stylus and stylar ventral barbs .

Variation. The pattern of spots may be somewhat reduced, as a thinner stripe boarding lateral margin, leaving isolated blots forming a circle in mesotergum.

SIBAMBEA WAORANI MEDRANO, KURY & MENDES

Figures

Figure 26. Map of known distribution of Sibambea and Marronia. Numbers correspond to the following WWF ecoregions: 1 = Eastern Cordillera real montane forest, 2 = Napo moist forest, 3 = Iquitos Várzea, 4 = Southwest Amazon moist forest, 5 = Solimões-Japura moist forest, 6 = Caquetá moist forest, 7 = Purus Várzea, 8 = Uatuma-Trombetas moist forest, 9 = Amazon-Orinoco Southern Caribbean mangroves.

Figure 44. Sibambea rotunda, male (CAS AK 003). A, dorsal view. B, lateral view. C, panoramic dorsal view. Scale bars: 1 mm.

Figure 45. SEM images of some structures of Sibambea rotunda, male (CAS AK 003). A–C, penis: A, dorsal view; B, lateral view; C, ventral view. D, left basichelicerite, dorsal view. E, left cheliceral hand, dorsal view. F, left pedipalpus, ventral view of tibia. G, same, mesal view. Scale bars: 50 μm (A–C), 100 μm (D), 200 μm (E–G). Abbreviation: MS = macrosetae.