Marayniocus martensi, Acosta, 2006

Acosta, Luis E., 2006, Marayniocus martensi, a new genus and a new species of Peruvian harvestmen (Arachnida: Opiliones: Gonyleptidae), Zootaxa 1325, pp. 199-210 : 203-206

Marayniocus martensi sp. n.

Figs 1–10

Acrographinotus luteipalpis: Roewer 1959: 74 , misidentification, in part (only some material from Hacienda Maraynioc belongs to Marayniocus martensi sp. n., the rest is referred to Junicus gerhardi , see below).

Type series: ♂ holotype, 1 ♂ and 1 ♀ paratypes ( SMF) [ex RII 12767/134] ; 1 ♂, 2 ♀ paratypes ( FML 00053) and 1 ♂ paratype ( CDA 000.803) [both ex Coll. Weyrauch, brittle and badly preserved]: Central Peru, Hacienda Maraynioc (3500 m), east slope of the Andes , basin of the río Chanchamayo , east of Tarma , under stones in grassland, 10.x.1956 (W. Weyrauch coll.). The label of RII 12767/134 only states " Perú, Río Chanchamayo" (Weyrauch’s label not retained) but full details (as in Roewer 1959) are given in the RII card catalog. After separating the types of M. martensi sp. n., the vial RII 12767/134 now contains one unidentified ♀ (probably belonging to Acrographinotus ).

Type locality: Hacienda Maraynioc (3500 m, circa 11°20’S 75°24’W), Departament Junín, Province Tarma , Peru. This locality is situated in the upper basin of the río Aynamayo , which flows into the río Chanchamayo near San Ramón. The valley of the río Tarma , also a subsidiary of the Chanchamayo, is located a few kilometers west of Hacienda Maraynioc, but is separated by a mountain range with altitudes higher than 4000 m .

Etymology: I am pleased to dedicate this new species to Prof. Dr Jochen Martens, as an acknowledgement of his many and meaningful contributions to the systematics of harvestmen, and especially for his kind Gastfreundlichkeit (hospitality), which enabled me to have a pleasant and fruitful time in his laboratory in the early 90s, during a research stay in Germany supported by the DAAD (Deutscher Akademischer Austauschdienst).

Description: Measurements. Dorsal scutum length: ♂♂ 6.0–6.7 (n=4), ♀♀ 5.9–6.0 (n=3). Detailed measurements of ♂ holotype and ♀ paratype: Table 1.

Color. General color yellowish­straw. Prosoma with faint pigment reticulation, this extending even fainter to lateral scutal borders, area V and free tergites; most of scutum very pale. Chelicerae and pedipalps with tenuous pigment reticulation. Legs I–III and leg IV of ♀ of the general color. Leg IV of ♂: Coxa similarly colored as scutum in its basal 2/3 (approximately at level of origin of apophyses); distal third, including apophyses, becoming abruptly darker (with definite transverse limit between the two tones); trochanter as dark as distal part of coxa, especially on dorsolateral apophyses; femur, patella and tibia slightly lighter, and in contrast to coxa and trochanter, ventral apophyses lighter (dorsal apophysis of femur of same coloration as rest of the article); metatarsus and tarsus of the general color. Ventral surface of body like light portion of coxa IV, except for darker borders of coxa­trochanter articulation and sternites.

Exomorphology. Prosoma and scutum sparsely set with tiny granules. Ocular mound with a tall apophysis ( Fig. 3). Scutum ( Figs 1, 6): Areas I –IV with a pair of paramedian granules, these minute in area I, increasing in size towards area IV. Lateral areas of scutum with a row of blunt granules and a fine, more mesal granulation. Area V and free tergites I–II ( Figs 1, 6) with a row of spaced grains, these smaller and rounded in area V, becoming more conical posteriorly in the ♂. Free tergite III with a row of small apophyses and a large median apophysis, this larger in the ♂ ( Figs 1, 4) than in the ♀ ( Fig. 6). Dorsal anal plate with two central grains, and with several small granules on the border; ventral anal plate with a row of granules along the edge (median ones largest). Shape and development of chelicerae and pedipalps as usual in the subfamily; pedipalp femur without medial subapical spine; tibia in dorsal view slightly more dilated than more basal articles (more pronounced in the ♀). Legs I –III unarmed, tibia III with 2–3 acute retroapical granules. Number of tarsomeres: 6:8–9:7:7 (holotype with 6:9/8:7:7) .

Leg IV of ♂. Coxa very dilated, its surface smooth, bearing a strong prolateral apophysis, diagonal and slightly inclined upwards ( Figs 1, 5); retrolateral apophysis quite large, opposed to an apophysis on the following article ( Fig. 2). Trochanter with two large prodorsal apophyses, the proximal smaller, the distal pointing more upwards and posteriad ( Figs 1, 5); an acute retrolateral apophysis in the basal half (opposed to retrolateral apophysis of coxa); retroventral apical apophysis of similar size, accompanied by a conical tubercle situated more ventrally. Femur with a strong dorsal apophysis in the middle third ( Fig. 5), its position determining a mild break in the article’s axis ( Fig. 1); basal part of femur more slender and smooth than portion posterior to apophysis, the latter dorsally with granulose surface; proventral row with a large leaf­shaped apical apophysis followed by 2–3 acute apophyses ( Fig. 2); this row continued anteriorly by acute grains from level of the large dorsal apophysis; retroventral subapical apophysis large, spur­like and diagonally inclined ventrad ( Figs 1–2, 5), on its base bearing an acute tubercle; after a gap, continued anteriorly into a retroventral row of apophyses of decreasing size, almost reaching base of femur; apex with three rudimentary dorsal apophyses. Patella dorsally covered with large, rounded granules ( Fig. 5); a large leaf­shaped ventral proapical apophysis, an acute ventral retroapical one, and a small prolateral apophysis ( Fig. 2). Tibia straight in dorsal view, slightly S­shaped in lateral view ( Fig. 5); dorsal surface with granulation similar to that on patella; a large, spur­like retroventral apophysis situated between middle and distal thirds of article; noticeable retro and proapical apophyses.

Leg IV of ♀. Coxa ( Fig. 6) with acute prolateral apophysis; small retrolateral apophysis less conspicuous because of proximity to sternites. Trochanter only with a small retroventral apophysis and a rudimentary retrolateral apophysis. Femur, patella and tibia of more spiny appearance than in ♂ ( Figs 6–7). Femur with granular dorsal surface and a proventral row of acute apophyses, these decreasing in size proximally; retroapical apophysis well­developed ( Fig. 6). Patella and tibia with acute apophyses on all surfaces ( Fig. 7), proapical one on patella enlarged.

Genitalia. Penis. Trunk simple, cylindrical. Ventral plate subrectangular, distal and lateral borders straight ( Fig. 10); marginal spine­shaped setae in two groups on each side: 3 apical setae with upwards­curved tips, and 4–5 thick and tortuous, longitudinally arranged basal setae; small rudimentary setae between these two groups and ventrally of the apical group ( Fig. 8). Glans arising from an expansion of the trunk, its subproximal portion strongly dilated, subspherical in dorsal view ( Fig. 10); VPS expanded in the form of a concave fan resembling a clam valve ( Fig. 10); ventral surface of the “fan” subterminally bearing an acute projection pointing downwards ( Figs 8–9).