Otxuruu fallax sp. nov.

Figs 1–10

Type material. Holotype ♂ from Floresta Nacional de Carajás, Cave N5S_0076 (GEM-1091) (6°05'26''S, 50°08'00''W), Parauapebas, Pará, Brazil, 14.III–04.IV.2010, R. Andrade et al. coll. (IBSP 174325). Paratypes: 1♀, same locality as the holotype (except 06°02'13"S, 50°15'59"W), 02–29.V.2015 (IBSP 208661); 2♀, same locality as the holotype (except Cave N5S_0071 (GEM-1086)), 25.VIII–03.IX.2009, R. Andrade et al. coll. (IBSP 289589); 1♀, same locality as the holotype (except Cave N4WS_0004 (GEM-1156), 6°04'21''S, 50°11'43''W), 18.XI– 01.XII.2010, F.P. Franco et al. coll. (MPEG. ARA 40842); 1♂ from Serra Tapirapecó [1°9'55"N, 64°58'15"W], Barcelos, Amazonas, Brazil, 29.XI.2010, R. Braga-Neto coll. (IBSP 279796); 1♀ from Altamira [3°12'01.3"S, 52°14'00.8"W], Pará, Brazil, IV.2011, M.E. Bichuette coll. (MPEG. ARA 40843).

Additional material examined. BRAZIL, Pará: Canaã dos Carajás: Cave S11C_0168 (06°22'49"S, 50°22'35"W), 21.IV.2016, BioEspeleo Consultoria Ambiental coll., 1♀ (IBSP 193167); Cave SB_0230 (6°20'34''S, 49°59'43''W), 13–23.II.2014, C.A.R Souza & J. Mascarenhas et al. coll., 1♀ (IBSP 174380); Paraupebas: Cave N4WS_0004 (GEM-1156) (6°04'21''S, 50°11'43''W), 10–19.V.2011, F.P. Franco & C.A.R. Souza et al. coll., 1♀ (IBSP 177775); Cave N5PSE-04 (PESE_0004 ou GEM-1864) (6°06'19''S, 50°09'06''W), 10–19.V.2010, I. Cizauskas et al. coll., 1♀ (IBSP 177777); Cave N5PSL-01 (PESL_0001 ou GEM-1866) (6°04'07''S, 50°08'40''W), 10–19.V.2011, I. Cizauskas et al. coll., 1♀ (IBSP 177778); Cave N5S_0069 (GEM-1084), 25.VIII–03.IX.2009, R. Andrade et al. coll., 1♀ (IBSP 289587); Cave N5S_0071 (GEM-1086), 14.III–04.IV.2010, R. Andrade et al. coll., 2♀ (IBSP 289590); Cave N5S_0082 (GEM-1087) [6°4'5.5"S, 49°54'15"W], 14.III–04.IV.2010, R. Andrade et al. coll., 1♀ (IBSP 289591); Cave N5S_0078 (GEM-1093) (6°06'08''S, 50°08'14''W), 14.III–04.IV.2010, R. Andrade & I. Cizauskas et al. coll., 1♀ (IBSP 174324); Cave N5S_0079 (GEM-1094), 15–21.IX.2009, R. Andrade et al. coll., 1♀ (IBSP 289588); Cave N5SM2_0087 (GEM-1733) (06°07'15''S, 50°07'43''W), 16.III.2011, R. Zampaulo coll., 1♀ (IBSP 190846); Cave N5SM2_0096 (GEM-1698) (06°08'06''S, 50°08'11''W), 29.XI.2010, R. Zampaulo coll., 1♀ (IBSP 190848); 03.V.2011, R. Zampaulo coll., 1♀ (IBSP 190849). ECUADOR, Zamora Chinchipe: Zamora: Copalinga Lodge (04°5'26.9"S, 78°57'29.50"W), 1–2.II.2018, A. Anker & P.H. Martins coll., 1♀ (UFMG 28131).

Etymology. The specific epithet is a Latin adjective meaning “deceiver”, in reference to a set of finger-like lobules at the posterior region of the opisthosoma that resembles spinnerets, which are instead located ventrally.

Diagnosis. See diagnosis for the genus, which is monotypic.

Description. Male (based on the holotype IBSP 174325): Carapace dark brown with a beige median spot extending from the central area of the cephalic region to the posterior margin of the carapace, as wide as half the carapace width, bearing a v-shaped brown spot on the thoracic region (Figs 6A, C); mouthparts and sternum orange. Legs orange with brown spots prolaterally on legs I–III and retrolaterally on leg IV (Figs 6A, C, E). Opisthosoma with six dorsolateral conical tubercles and a set of posterior finger-like lobules, arising over a common base; dorsum dark grey with two anterior irregular grey spots in line with the first pair of dorsolateral tubercles and another pair of posterior irregular grey spots in line with the second pair of tubercles and many small gray spots over the dorsum; sides and venter beige (Figs 5A, C, 6A, C, E). Palp (Figs 7, 9A–C): see description for the genus. Total length: 2.75. Carapace 1.27 long, 0.96 wide, 0.49 high. Sternum 0.54 long, 0.45 wide. Eye diameters and interdistances: AME 0.15, ALE 0.09, PME 0.09, PLE 0.09, AME–AME 1/3 AME diameter, AME–ALE 1/3 AME diameter, ALE–PLE contiguous, PLE–PLE 1/2 PLE diameter, PME–PLE 1/2 PME diameter. Leg formula 1243. Leg length total (femur, patella, tibia, metatarsus, tarsus): I: 2.83 (0.88, 0.37, 0.56, 0.6, 0.43); II 2.20 (0.69, 0.30, 0.44, 0.43, 0.34); III 1.62 (0.47, 0.27, 0.27, 0.26, 0.34, 0.29); IV 2.01 (0.63, 0.29, 0.41, 0.41, 0.29). Opisthosoma 1.56 long, 1.57 wide, 1.07 high.

Female (based on the paratype IBSP 208661): Cephalothorax same color as in male (Figs 6B, D). Legs and opisthosoma same color as in male (Figs 5B, D, 6B, D, F). Chelicera with three teeth on promargin and two teeth on retromargin and a field of denticles on fang furrow (Fig. 2F). Epigyne (Figs 8, 9D–F): see description for the genus. Total length: 3.33. Carapace 1.27 long, 1.0 wide, 0.46 high. Sternum 0.61 long, 0.54 wide. Eye diameters and interdistances: AME 0.13, ALE 0.10, PME 0.15, PLE 0.10, AME–AME 1/3 AME diameter, AME–ALE 1/4 AME diameter, ALE–PLE almost contiguous, on a tubercle, PLE–PLE 1/3 PLE diameter, PME–PLE 1/3 PME diameter. Leg formula 1432. Leg length (femur, patella, tibia, metatarsus, tarsus): I: 2.77 (0.88, 0.43, 0.52, 0.53, 0.39); II 2.28, (0.71, 0.37, 0.42, 0.43, 0.35); III 1.64, (0.47, 0.27, 0.27, 0.25, 0.35, 0.31); IV 2.43, (0.81, 0.39, 0.46, 0.43, 0.33). Opisthosoma 2.17 long, 2.59 wide, 1.82 high.

Natural history. Most specimens were collected within caves in iron formations in Serra dos Carajás, Pará, Brazil. At least one specimen was collected outside caves at the Copalinga Lodge, Zamora Chinquipe, Ecuador, found resting on a silk thread in a microhabitat formed by a hollow in an embankment within a forested area (Fig.1), indicating O. fallax sp. nov. as a troglophile species.

Distribution. Known from Ecuador and Brazil (Fig. 10).