Metalibitia tibialis Roewer 1925
Creators: name: Coronato-Ribeiro, Amanda
name: Pinto-Da-Rocha, Ricardo
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Opiliones
Cosmetidae
Metalibitia
Metalibitia tibialis

description: Metalibitia tibialis (Roewer, 1925)
(Figs: 2D; 4B, E; 6D, I; 8D, I; 13A–C)
Libitiola tibialis Roewer, 1925: 9 [desc], fig. 7; 1927: 612 [rdesc], fig. 42
Metalibitia tibialis: Ringuelet, 1959: 423 [rdesc], fig. 62; H. Soares, 1966b: 127 [cit]; Soares & Soares, 1987: 2 [syst], figs. 8– 9; Kury, 2003: 69 [cat]; Pinto-da Rocha & Hara, 2011: 3 [cit]
Metalibitia oranensis H. Soares, 1966b: 127 [desc], figs 2, 2a; Soares & Soares, 1987: 2 [cit]. Synonymy established by Soares & Soares, 1987.
Type material. Libitiola tibialis: MZT, ♂ “type”, not examined; SMF RII 122/4 2♂ paratype, examined. M. oranensis: HSPC (MNRJ) 69, ♂ holotype, examined; MZSP, paratype, not examined (lost).
Type locality. L. tibialis: ARGENTINA, Jujuy Province, “ San Lorenzo ” (nowadays Libertador General San Martín). M. oranensis: ARGENTINA, Salta Province, Orán: Aguas Blancas.
Geographical distribution (Fig. 14). Limited to southeast region oF Bolivia, Santa Cruz (Lagunillas), northwestern region oF Argentina, Jujuy Province (San Lorenzo) and Salta Province (Oran).
Diagnosis. Resembles M. adunca in having tibia IV with two apophyses with pointed apex on ventral region (Figs 7 E; 8I); M. borellii in having a row oF similar sized tubercles on Free tergite II (Fig. 1 C; 2D) (M. adunca has two rhomboid tubercles, Fig. 1 A), one rounded tubercle on retroapical region oF Femur IV (Figs 5 G; 6I) (M. adunca has one retroapical ventral row oF six tubercles, Followed by ventroapical apophyses, Fig. 5 E). DiFFers From these species in having two retroapical tubercles Fused at base on cheliceral bulla (Fig. 2 D) (M. adunca and M. borellii have only one tubercle, Figs 1 A, C), Free tergite III unarmed and inFlated, being higher than other tergites (Fig. 2 D) (M. adunca and M. borellii have all Free tergites with similar sized tubercles; M. borellii has a high central tubercle with rounded apex, Figs 1 A, C), trochanter IV with one tubercle with rhomboid apex on retroapical ventral region (Fig. 6 I) (M. adunca has one tubercle with pointed apex on retrobasal region; M. borellii has two tubercles with pointed apex,one on retrobasal region and the other on retroapical region, Figs 5 E, G).
Redescription. Male (SMF 122/4)
Measurements (SMF 122/ 4 paratype): dorsal scutum, total length 4.2; dorsal scutum, total width 4.0; prosoma length 1.25; prosoma width 2.0; Femur I length 1.75; Femur II length 3.25; Femur III length 2.55; Femur IV length 3.1; pedipalpal Femur length 1.0 mm.
Coloration in ethanol: Entirely pale brown.
Dorsum (Fig. 2 D): Median region oF anterior margin oF dorsal scutum smooth, with three rhomboid tubercles Fused at base, near paracheliceral projections. Lateral margins oF dorsal scutum with rounded tubercles near areas I–IV. Ocularium with a shallow median depression, with 13 small tubercles. All areas covered with small tubercles, lateral regions oF areas smooth. Posterior margin oF dorsal scutum with row oF 17 tubercles. Free tergite I with row oF 16 tubercles, II with row oF 14 tubercles, III inFlated and smooth. Anal operculum with 21 tubercles irregularly scattered and row oF 14 tubercles on ventral border. All tubercles oF posterior margin oF dorsal scutum, Free tergites and anal operculum with rounded apex.
Chelicera (Fig. 2 D): Bulla with Five-Four rounded tubercles on basal margin, two–three retrolateral tubercles and two retroapical tubercles united at base. Segment II with Five teeth, segment III with three large teeth and two smaller ones.
Pedipalps (MZSP 67951) (Figs 4 B, E): Trochanter with one apical ventral tubercle. Femur with seven dorsal median tubercles, 12 prolateral tubercles, median row oF six ventral tubercles, and two apical retrolateral tubercles. Patella dorsally tuberculated, lateral retangular projection on the distal halF. Tibia with setiFerous tubercles, one proapical tubercle and one retroapical tubercle, prolateral apical rounded projection, one prolateral ventral apical macrosetae, ventral macrosetae. Base oF tarsus wider than apex, one row oF macrosetae on retrolateral ventral border and six macrosetae on prolateral ventral border.
Legs (Figs 2 D; 6D, I; 8D, I): Coxa I with one retrolateral basal tubercle smaller than prolateral one. Coxa II with prolateral tubercle with pointed apex pointing towards coxa apex and one smaller retrolateral tubercle with rounded apex. Coxa III with one long prolateral tubercle. Coxa IV visible only apically in dorsal view, tuberculated and with one dorsoapical apophysis. Trochanter IV with Four retroapical tubercles and lateral small tubercles, three ventrobasal retrolateral tubercles, one high rhomboid tubercle on ventroapical region, Followed by two smaller tubercles. Femur IV curved and covered with small tubercles, with dorsal prolateral row oF tubercles on its whole length, a large retroapical rhomboid tubercle, tubercles concentrated on the dorsal distal halF, two ventral rows oF tubercles with increasing size on distal portion, and three ventroapical tubercles. Tibia IV granulated, with dorsal tubercles concentrated in both lateral sides, with two retrolateral apophyses with pointed apex on ventral region, one retrobasal and one retromedian, interspersed by rhomboid tubercles, Followed by retroapical row oF tubercles; prolateral row oF tubercles, From base to apex. Tarsal Formula: 5 / 7 / 5 / 6.
Penis (MZSP 67951) (Figs 13 A–C): Truncus enlarged at the base oF ventral plate. Ventral plate narrowed on its middle one third, with distal margin and lateroapical borders convex. Three pairs oF minute ventral macrosetae, two apical and one on median region (group E); dorsal region with Four pairs oF macrosetae on median region, two apical pairs (group C), one median pair (group D) and one basal pair, near lateral membranous extension (group A). Glans narrowed at the base oF stylus and with apex bent dorsad.
Female (MZSP 67951)
Measurements: dorsal scutum, total length 3.7; dorsal scutum, total width 3.25; prosoma length 1.2; prosoma width 1.8; Femur I length 1.5; Femur II length 2.2; Femur III length 2.2; Femur IV length 2.7; pedipalpal Femur length 0.8 mm.
Dorsum: Ocularium with 17 tubercles. Posterior margin oF dorsal scutum with 22 tubercles. Free tergite I with 15 tubercles, median region smooth, II with 16 tubercles, III with 12 tubercles. Anal operculum with 31 tubercles. All tubercles with rounded apex. Chelicera: Bulla with Five basal tubercles. Pedipalps: Femur with one dorsal row with three tubercles, nine prolateral tubercles and three apical prolateral tubercles, ventral row oF seven tubercles. Two apical retrolateral tubercles. Leg IV: Trochanter with retrolateral small tubercles. Femur with small tubercles and apical small tubercle. Tibia with two retrolateral small apophyses. Tarsal Formula: 5 / 7 / 5 / 6.
Variation. There can be two or three tubercles on the laterals oF dorsal scutum anterior margin, near paracheliceral projections (sample SMF 122/4). The dorsal tubercles oF bulla can vary in size and number, being 4– 5 tubercles (sample HSPC (MNRJ) 69); tibia IV may have only retrobasal apophyses (sample HSPC (MNRJ) 69), smaller than other specimen (sample SMF 122-4). Measurements ♂ (n=3): dorsal scutum, total length 3.5–8.3; dorsal scutum, total width 3.2–4.1; prosoma length 1.0–1.3; prosoma width 1.75–2.0; Femur I length 1.5–1.8; Femur II length 3.0–3.2; Femur III length 2.3–2.7; Femur IV length 2.5–3.0; pedipalpal Femur length 0.8–1.0 mm. Measurements ♀ (n=3): dorsal scutum, total length 3.7–4.0; dorsal scutum, total width 3.2–3.7; prosoma length 1.2; prosoma width 3.5–4.0; Femur I length 1.5–1.7; Femur II length 2.6–2.7; Femur III length 2.2–2.5; Femur IV length 2.8–3.0; pedipalpal Femur length 0.7–1.0 mm. Tarsal Formula ♂ (n=3) 5/ 6–7/ 5/ 5–6. Tarsal Formula ♀ (n=3) 5/ 7/ 5–6/ 6.
Material examined. BOLIVIA. Santa Cruz Departament, Lagunillas, 19°38'54.9"S 63°41'09"W, 04.XII.2010, R. Pinto-da-Rocha, A. Benedetti, J. Ochoa & A. Sarabia leg., 7♂ 14♀ (MZSP 67951).
description: Published as part of Coronato-Ribeiro, Amanda & Pinto-Da-Rocha, Ricardo, 2017, Taxonomic revision and cladistic analysis of the genus Metalibitia Roewer, 1912 (Opiliones, Cosmetidae, Cosmetinae), pp. 201-242 in Zootaxa 4291 (2) on pages 229-231, DOI: 10.11646/zootaxa.4291.2.1, http://zenodo.org/record/829489