Charinus santandereanus

Description. Female. Carapace (Fig. 1 A – C). Frontal process triangular, not visible in dorsal view. Anterior margin straight, with six anterior setae. Median eyes and ocular tubercle absent. Lateral eyes well developed, pale, small seta posterior to each lateral ocular triad. Interocular region finely granulated. Sternum (Fig. 1 D). Tetra-segmented, all platelets markedly sclerotized. Tritosternum projected anteriorly into small, blunt tubercle, surpassing base of pedipalp coxae; medial platelet (tetrasternum) and third platelet (pentasternum) formed by single plates, each with a pair of large anterior setae and several smaller posterior setae; metasternum small, not paired, with pair of small setae, with seven setae in membranous region. Opisthosoma. Ventral sacs and ventral sac cover absent. Genitalia (Fig. 2). Female genital operculum with posterior margin slightly convex, with a slight medial indentation, and several setae along margin and on surface. Female gonopods whitish, membranous, cushion-like, with a slightly sclerotized ring-like area and apparently with a circular apical opening on each. With two posteromedial curved and sclerotized ducts. Chelicerae (Fig. 1 E, F). Mesal margin with four teeth: the fourth conspicuously largest, followed by the bifid first tooth, the second, and the third as the smallest. Ectal face with a small, blunt subdistal projection pointing frontally, aligned with the bifid tooth. Claw long, surpassing the fourth basal tooth, with a row of approximately five decreasing teeth. Cusps of the bifid tooth are approximately equal in size. Pedipalps (Fig. 1 G – K). Femur dorsally with two distinct setiferous tubercles proximal to spine 1; primary series with four dorsal spines, decreasing in size from 1 to 4; ventrally with two distinct setiferous tubercles proximal to spine 1, and primary series with three ventral spines decreasing in size. Patella with four dorsal spines, including a large setiferous tubercle distal to spine I, about one-third length of spine I; two ventral spines the distal larger; setiferous tubercles intercalated between the ventral spines, as well as anterior and posterior to them. Tibia with two dorsal spines, the distal spine twice the length of proximal spine; distal ventral spine on the tibia, with a more developed small setiferous tubercle in basal position, and three distinctive setae between them. Tarsus with two dorsal spines; proximal spine shorter than the distal spine. Legs. Tibia of leg I with 23 articles; tarsus I with 29 or 30 articles in incomplete legs. None of the specimens have a complete first leg. Leg IV basitibia with two pseudo-articles; trichobothrium bt situated in proximal third, near proximal margin; distal apex of basitibial pseudo-articles with dark, denticulate projection; distitibia trichobothrium bc situated closer to bf than to sbf; sc and sf series each with six trichobothria; tarsus with distinct white annulus distally on first article. Measurements. See Table 1.

Figs 1 A – K, 2 A, B, 14 A, 15

Diagnosis. Due to the exceptional species diversity and high endemism in Charinus, the diagnosis compares the new species with all three Colombian congeners (C. miskito, C. rocamadre, and C. mocoa) for regional differentiation, as well as with geographically proximate Venezuelan species that share its median-eyeless condition, ensuring comprehensive morphological and biogeographical context. Charinus santandereanus sp. nov. is diagnosed from Colombian congeners by the complete absence of median eyes (vs. reduced eyes in C. miskito), two pseudo-articles on leg IV basitibia (vs. three in C. rocamadre), and the first cheliceral tooth dentition subequal and dorsal margin concave (vs. dentition heterogenous, ventral denticle enlarged, and dorsal margin straight in C. rocamadre and C. mocoa). Among non-Colombian Venezuelan median-eyeless congeners, it differs from its morphologically closest relative C. camachoi (González-Sponga, 1998) by the distinct pedipalp femoral spine arrangement: femur with 4 dorsal spines (vs. 3 dorsal in C. camachoi) and patella with 5 dorsal spines (vs. 4 dorsal spines); differs from C. bordoni by retaining well-developed lateral eyes (vs. complete ocular absence in C. bordoni); from C. pardillalensis by pentasternum shaped like flattened platelets (vs. metasternum granular in shape) and differs from C. tronchonii in having fewer anterior carapace setae (6 in C. santandereanus vs. more than 6 in C. tronchonii) (Fig. 14 B) and femur with 4 dorsal spines (vs. 3 dorsal spines).

Distribution. Known only from the type locality.

Etymology. The specific epithet santandereanus refers to the type locality, the Department of Santander.