Metalibitia argentina Sorensen 1884
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 argentina

description: Metalibitia argentina (Sørensen, 1884)
(Figs: 1B; 3A; 5B, F; 7B, F; 11A–C)
Cosmetus argentinus Sørensen, 1884: 593 [desc]; Kury, 2003: 68 [cat].
Cosmetus Argentinus: Sørensen, 1895: 1 [cit]; Moritz, 1971: 191 [cit]; Kury, 2003: 68 [cat].
Paralibitia argentina: Roewer, 1912: 14 [cit]; 1923: 295 [rdesc]; 1927: 552 [cit]; Mello-Leitão, 1932: 90 [rdesc]; 1933: 109 [syst]; Moritz, 1971: 191 [cit]; Kury, 2003: 68 [cat].
Paralibitia maculata Roewer, 1914: 130 [desc], fig. 15; 1923: 295 [rdesc], fig. 316; 1927: 552 [key]; Mello-Leitão, 1932: 90 [rdesc], fig. 58; Weidner, 1959: 128 [cit]; Kury, 2003: 69 [cat]. New synonymy
Libitia (Messa) argentina: Sørensen, 1932: 412 [syst]; Kury, 2003: 68 [cat].
Labrosa arenosa Mello-Leitão, 1939: 294 [desc], fig. 17; Kury, 2003: 68 [cat] [syst]. New synonymy
Metalibitia maculata: Ringuelet, 1959: 425 [cit]; Kury 2003: 69 [cat]; Pinto-da- Rocha & Hara, 2011: 3 [cit].
Metalibitia argentina: Ringuelet, 1959: 418 [rdesc, syst, cit], fig 60; Valentinis de Martínez, 1974: 6 [cit]; Kury, 2003: 68 [cat].
Metalibitia arenosa: Kury, 2003: 68 [cat, syst].
Type material. Cosmetus argentinus: ZMUC, ZMB 8391 syntypes (Kury, 2003). Syntype ZMB 8391 examined From photo. M. maculata: ERPC holotype; ZMH, SMF RI, paratypes. Paratype ♂ SMF examined. M. arenosa: holotype ♂ with depository unknown.
Type locality. M. argentina: ARGENTINA, Buenos Aires Province, San Nicolas, Santa Fe Province, “on the way to Villa Hernandaria ” [Hernandarias], and Chaco Province, near “ Baranjeras ” [Barranqueras] (Sørensen, 1884). M. maculata: PARAGUAY, San Bernardino District. M. arenosa: BRAZIL, Mato Grosso do Sul State, Salobra River (20°11'S 56°31'W, 215 m).
Geographical distribution (Fig. 14): Studied localities are restricted to northeastern Argentina, provinces oF Chaco (Resistencia) and Buenos Aires (San Nicolas), western Paraguay (Rio Apa) and Department oF Cordillera (San Bernardino) and midwestern Brazil (Mato Grosso do Sul State).
Diagnosis. Resembles M. brasiliensis in having retrolateral tubercles on middle region oF trochanter IV (Figs 5 B, D, F, H) and M. borellii in having Free tergite III with central tubercle larger than the others (Figs 1 B, C); it recalls both species in having tibia IV unarmed (Figs 7 B–D). Distinguished From the reFerred species in having median tubercles on trochanter IV spaced (Figs 5 B, F) (in M. brasiliensis these tubercles are placed close to each other, Figs 5 D, H; M. borellii has one basal and one apical tubercle, Figs 5 C, G); also by central tubercles oF Free tergite III larger than the other ones (Fig. 1 B) (M. brasiliensis has similar sized tubercles, Fig. 1 D), and Femur IV unarmed (Figs 5 B, F) (M. borellii has an apical tubercle, Figs 5 C, G).
Redescription. Male (MACN 4497)
Measurements: dorsal scutum, total length 3.7; dorsal scutum, total width 3.9; prosoma length 1.4; prosoma width 2.2; Femur I length 1.7; Femur II length 2.8; Femur III length 2.5; Femur IV length 3.3; pedipalpal Femur length 0.8 mm.
Coloration in ethanol: Entirely pale brown, legs slightly lighter than dorsal scutum.
Dorsum (Fig. 1 B): Median region oF anterior margin oF dorsal scutum smooth, two high and truncated tubercles near paracheliceral projections. Lateral margin oF opisthosoma with rounded tubercles on areas I–IV. Domed ocularium (i.e., without a median depression), with ten small tubercles. Scutal area IV with a pair oF paramedian small spines with rhomboid apex. Posterior margin oF dorsal scutum with a row oF 18 tubercles. Free tergite I with row oF 17 tubercles, II with row oF 13 tubercles, III with row oF eight tubercles, the median one larger than the others and Formed by three joint tubercles. Anal operculum with 18 irregularly scatterd tubercles. All tubercles oF posterior margin, Free tergites and anal operculum with rounded apex.
Chelicera (Fig. 1 B): Bulla with Five rounded tubercles on proximal margin, one probasal tubercle (on leFt side), small lateral tubercles and two prolateral apical tubercles Fused. Finger oF segment II with Four teeth, segment III with Five teeth.
Pedipalps (Fig. 3 A): Trochanter with two apical ventral tubercles united at the base. Femur with 12 dorsal setiFerous tubercles; dorsal prolateral row oF Four setiFerous tubercles; ventral row oF Five setiFerous elongated tubercles, being the median two larger than the others; three setiFerous ventroapical tubercles. Tibia with small dorsal setiFerous tubercles, a small prolateral apical rounded projection, one dorsoapical tubercle on each side, one ventral prolateral spine and a row oF seven ventral retrolateral setae. Tarsus with dorsal and lateral setae, Five prolateral ventral setae, Four retrolateral ventral setae and 11 ventral setae.
Legs (Figs 1 B; 5B, F; 7B, F): Coxa I with one prolateral basal long FalciForm tubercle (reaching the coxa apex) and one smaller basal retrolateral tubercle. Coxa II with prolateral tubercle with rhomboid apex directed towards apex oF the coxa and one tubercle with rounded apex, smaller than retrolateral one. Coxa III with one prolateral tubercle. Coxa IV visible in dorsal view, tuberculated, with one dorso-apical apophysis and three retroapical ventral tubercles. Trochanter IV with small retrolateral tubercles, Four retroventral tubercles (two apical united at their base) and one ventroapical tubercle. Femur IV curved and entirely granulous, with tubercles more concentrated on dorso-retrolateral region. Patella and tibia IV tuberculate, with long tubercles on dorsal side. Tarsal Formula: 5 / 7 / 5 / 6.
Penis (Figs 11 A–C): Truncus with truncated enlargement at the junction with ventral plate. Ventral plate with gentle concavity on distal margin, with two pairs oF micro-spines on ventrodistal region and one pair oF macrosetae E in median-ventral region. Five pairs oF macrosetae on median region to distal region oF ventral plate, two subapical pairs (macrosetae C), one dorso-median pair (macrosetae D), one lateral pair (macrosetae B) and one dorsobasal pair (macrosetae A). The membranous projection extended on the basal halF oF ventral plate. Insertion oF glans dorsally on middle oF ventral plate. Glans wide, slightly Flattened dorso-ventrally; base oF stylus narrowed. Stylus narrow, long, with thin and smooth apex.
Female (MACN 4496)
Measurements: dorsal scutum, total length 3.5; dorsal scutum, total width 3.2; prosoma length 1.1; prosoma width 1.7; Femur I length 1.6; Femur II length 2.9; Femur III length 2.2; Femur IV length 2.7; pedipalpal Femur length 0.7 mm.
Dorsum: Posterior margin oF dorsal scutum with a row oF 25 small tubercles, with rounded apex. Free tergite I with 22 tubercles, II with 16 tubercles, III with 10 similar sized tubercles. Anal operculum with 25 tubercles irregularly scattered. Pedipalps: Femur with dorsal proximal projection reaching the median region, Formed by small tubercles and Followed by three dorsoapical tubercles; ventral row oF six tubercles and two apicoventral tubercles. Legs: Coxae with small tubercles. Coxa IV with ventral region smooth. Trochanter IV smooth. Body entirely little tuberculated. Tarsal Formula: 5 / 7, 6 / 5 / 6.
Variation. Cheliceral bulla oF males can have 4 to 6 proximal tubercles. Tarsus oF pedipalp can have six prolateral spines and two retrolateral spines. Coxa III can have small retrolateral tubercle united to coxa IV. The trochanter IV can have up to Five retrolateral tubercles and up to one apical tubercle, the tubercles may or may not be arranged in a row. The ventral plate oF penis may have two pairs oF dorsal median macrosetae (group D). Measurements ♂ (n=4): dorsal scutum, total length 3.5–3.8; dorsal scutum, total width 3.4–3.8; prosoma length 1.1–1.2; prosoma width 1.9–2.2; Femur I length 1.6–2.1; Femur II length 3.1–4.0; Femur III length 2.6–3.2; Femur IV length 2.9–3.4; pedipalpal Femur length 0.7–0.9 mm. Measurements ♀ (n=3): dorsal scutum, total length 3.3– 3.9; dorsal scutum, total width 3.2–3.4; prosoma length 1.0–1.1; prosoma width 1.7–1.9; Femur I length 1.7–2.3; Femur II length 3.2–3.5; Femur III length 2.5–2.7; Femur IV length 3.0–3.2; pedipalpal Femur length 0.8–0.9 mm.
Synonymic note: Metalibitia maculata was described based on one male and is hereby synonymized with M. argentina based on morphological similarities: coxae I and II with retrolateral and prolateral tubercles, Free tergite III with median tubercles larger than the others, cheliceral bulla with two proapical tubercles Fused, trochanter IV with Four retroventral tubercles, the two apical Fused at their base, truncus oF penis with small enlargement at the junction with ventral plate, the latter with slight concavity on its distal margin, same number oF macrosetae groups A, B, C and E, glans elongated and wide. Variation in group D oF penis macrosetae was observed (unambiguous homoplastic synapomorphy, Fig. 15), may have two pairs oF dorso-median macrosetae. M. arenosa was described based on one male specimen and is here synonymized with M. argentina based on morphological similarities: presence oF a pair oF spines on area III, Free tergite III with median tubercle larger than others, absence oF subapical tubercle on Femur IV and trochanter IV with retrolateral tubercle, these Features are according to its original description (Mello-Leitão, 1939), because the type material is lost. Both synonymized species have a similar or near geographical distribution to M. argentina.
Material examined. ARGENTINA. Chaco Province, Resistencia, 27°27'06.3"S 58°59'14.2"W, XII.1944, Cranwell leg., 1♂ 2♀ (MACN 4496); same loc., 18/ 20.VI.1934, J.B. Daguerre leg., 3 ♂ (MACN 4497), same loc., 18.VIII.1955, J. B. Daguerre leg., 12♂ 24♀ (MACN 4499). PARAGUAY. Apa River, 22°06'21.2"S 56°30'30.9"W, no date, no leg., 2♂ (SMF 5856 /167); same loc., Cordillera Departament, San Bernardino, 25°18′38″S 57°17′46″W, no date, no leg., 1♂ (SMF 1075).
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 213-217, DOI: 10.11646/zootaxa.4291.2.1, http://zenodo.org/record/829489