Megalopsalis serritarsus Sørensen 1886

Taylor, Christopher K., 2011, Revision of the genus Megalopsalis (Arachnida: Opiliones: Phalangioidea) in Australia and New Zealand and implications for phalangioid classification 2773, Zootaxa 2773 (1), pp. 1-65 : 32-34

Megalopsalis serritarsus Sørensen 1886

( Figs 35–36 , 39 , 45–51 )

Macropsalis serritarsus Sørensen 1886: 55–56 , pl. 5, fig. 1— Roewer 1911: 103, 1912: 279, pl. 4, figs 22–23.

Megalopsalis serritarsus (Sørensen) — Roewer 1923: 867, fig. 1033, 1956: 267; Weidner 1959: 126; Hunt 1990: fig. 3d; Crawford 1992: 28 (by implication).

Material examined. Male lectotype (designated by Weidner 1959). Sydney , New South Wales, Australia ( ZMH) .

Other material examined. 1 male, 1 female, under rocks, Blackheath, Blue Mts , New South Wales, 6 June 1982, V . E. Davies ( QM S2978 ) ; 1 male, Beecroft Peninsula, northern headland of Jervis Bay , New South Wales, 35°03'03"S 150°47'51"E, 11–15 August 1999, L. Gibson, pitfall traps ( AMS KS63527 ) ; 1 male, Booderee National Park, southern headland of Jervis Bay , New South Wales, 35°08'49"S 150°45'05"E, 11–15 August 1999, L. Gibson, pitfall traps ( AMS KS62923 ) .

Diagnosis. Megalopsalis serritarsus can be distinguished from M. leptekes and M. hoggi by the presence of ventrodistal bulges on the pseudosegments of distitarsus II, from M. pilliga by the presence of distinct armature on femur II, and from M. epizephyros by the lack of spines on the pedipalpal femur. Definitively distinguishing M. serritarsus from M. eremiotis requires examination of the spiracle: M. serritarsus has less slender spines across the spiracle and the lace tubercles are shorter but more extensive. However, no specimens of M. serritarsus have been recorded with ventral spines on the pedipalpal femur, as found in some specimens of M. eremiotis , and the two species are allopatric.

Description. MALE (N = 3). Prosoma length 1.39–1.70, width 2.00–2.18, entire body length 2.97–4.15. Dorsal prosomal plate and anterior half of lateral shelves mottled orange-brown with iridescent white reticulation on anterior propeltidium. Spines on anterior and posterior propeltidium, median propeltidium unarmed except few spines on lateral margin of dorsal prosomal plate. Ocularium white but with black eyes visible through cuticle. Ocularium spinose. Small iridescent white postocularial marking. Anterior margin of mesopeltidium medially curved anteriad. Mesopeltidium, metapeltidium and opisthosoma with broad iridescent white medial stripe. Metapeltidium, posterior half of lateral shelves and opisthosoma laterally light grey-brown with irregular tan punctures. Mouthparts white; coxae light orange. Coxa I ventrally spinose. Venter of opisthosoma cream with purple median stripe on genital operculum.

Chelicerae. Segment I 4.53–4.85, segment II 5.56–6.00. Long, slender, with segment II slightly inflated distally; both segments tan with dark brown markings on segment II; evenly denticulate. Cheliceral fingers short; mobile finger angular crescent-shape (fig. 47).

Pedipalps. Femur 1.67–1.73, patella 0.80–0.84, tibia 0.97–1.11, tarsus 1.92–2.01. Femur and patella medium brown with black patches, tibia tan with black shading, tarsus cream. Trochanter with few dorsodistal spines; remainder of pedipalp unarmed. Patella with rounded apophysis about half length of patella body (fig. 48), tip of patellar apophysis black; medial side of patella and tibia densely setose. Microtrichia on distal two-thirds of tarsus; claw with ventral tooth row.

Legs. Leg I femur 3.56–3.94, patella 1.18–1.24, tibia 3.05–3.30; leg II femur 5.88–6.38, patella 1.31–1.41, tibia 5.66–5.85; leg III femur 2.94–3.34, patella 0.89–1.09, tibia 2.34–2.45; leg IV femur 5.00–5.81, patella 1.07–1.32, tibia 3.70–3.88. Trochanters I and II with dense arrangement of spines on anterior faces; trochanters III and IV unarmed. Femur I orange, densely denticulate, with proventral row of longer spines down entire length; patella I and tibia I mottled gold and brown with proventral spine row along entire length of patella and tibia, smaller dorsal spine row along patella and proximal half of tibia; metatarsus I and tarsus I cream with ventrodistal black markings on metatarsus. Femur II tan with ventral and dorsal rows of small spines, dorsal row for proximal two-thirds only, ventral for proximal two-thirds or entire length, scattered extra spines in proximal half; patella II and tibia II golden cream with brown patches, tibia not divided into pseudosegments; metatarsus II and tarsus II cream with ventrodistal bulges on proximal pseudosegments of tarsus. Femora III and IV proximally tan, distally orange; patellae and tibiae III and IV golden orange with brown patches; metatarsi and tarsi III and IV cream. Femur III unarmed or with sparse dorsal row of small spines, occasionally small number of small spines distally; remaining segments unarmed. Tarsi III and IV proximally inflated, with double ventral rows of brush-like setae.

Penis (figs 49–51). Posterior bristle groups elongate. Glans strongly dorsoventrally flattened in some specimens.

Spiracle (figs 35–36). Anterior spines extending only partway across spiracle. Spines reticulate laterally, becoming less so medially; terminations simple or slightly palmate.

FEMALE (N = 1). Prosoma length 1.34, width 2.13; entire body length 5.44. Articular membranes iridescent white. Background of dorsal prosomal plate iridescent white with light brown paired stripes between ocularium and anterior margin; median propeltidial area with light brown central patch behind boundary with anterior propeltidial area, light brown stripe in front of boundary with posterior propeltidial area, beginning slightly laterally from ocularium and extending two-thirds of distance to lateral edge of plate; posterior propeltidial area with dark brown patches towards lateral edge of dorsal prosomal plate, and with rows of light patches in front of junction with mesopeltidium becoming progressively more elongate laterally. Ocularium white. Lateral shelves white with medium brown patches in front of, medially from and posterior to ozopore alongside junction with dorsal prosomal plate, and with dark brown lateral stripe from anterior corner of prosoma to front of anterior ozopore lobe. Mesopeltidium, metapeltidium and dorsum of opisthosoma mottled light grey-brown and white with broad medial stripe of white dusted with purple. Mouthparts cream; coxae white, spotted with light brown, thin medial stripe of dusted dark purple on proximal third, dusted black patch retrodistally; genital operculum cream with light brown medial stripe; venter of opisthosoma mottled white and light grey-brown with grey-brown patches darkening to light brown along midlines of segments.

Chelicerae. Segment I 0.95, segment II 1.82. Segment I ventrally white, dorsally white, spotted with light brown distally and with dark purple lateral stripe narrowing distally; segment II cream with lateral light brown patches in herringbone pattern for proximal two-thirds; both segments unarmed.

Pedipalps. Femur 1.82, patella 1.04, tibia 1.14, tarsus 2.18. Basal quarter of femur white, following third light brown, distal remainder white with medium brown band starting quarter of length from distal end and with dark brown retrodistal spot; patella golden brown with cream patches distally; subcylindrical mediodistal apophysis on patella of slightly lesser length than patella body, apophysis cream with dark brown distal end; proximal part of tibia mottled golden brown and cream; distal end of tibia and tarsus cream.

Legs. Leg I femur 3.04, patella 1.13, tibia 2.78; leg II not preserved; leg III femur 2.72, patella 1.01, tibia 2.13; leg IV femur 4.85, patella 1.17, tibia 3.48. Femora proximally mottled white for most of length; distal end of femora to tibiae cream with mottled medium brown patches; basitarsus banded cream and light brown with dark brown band at distal end; distitarsi cream. All segments unarmed. Tibia IV without pseudosegments; tibia II not preserved.

Comments. The holotype of this species is very poorly preserved, and very few of its diagnostic features remain distinguishable. The specimens described herein have been assigned to this species on the basis of their distribution close to the reported type locality.

Figures

FIGURES 35–38. Spiracles of Megalopsalis species. 35. Megalopsalis serritarsus, entire spiracle. 36. Same, close-up of lateral corner. 37. Megalopsalis eremiotis, close-up of lateral corner. 38. Megalopsalis epizephyros, close-up of lateral corner.

FIGURES 39–40. Modified distitarsi in Megalopsalis species. 39. Megalopsalis serritarsus (AMS KS63527), distitarsus II showing distoventral bulges on pseudosegments (scale bars = 1 mm). 40. Megalopsalis epizephyros, close-up of two pairs of brush-like setae on ventral side of distitarsus IV.

FIGURES 45–51. Megalopsalis serritarsus (Sørensen 1866), male. 45. Body, dorsal view (AMS KS63527). 46. Body, including chelicera, pedipalp and leg I, lateral view (AMS KS63527). 47. Right cheliceral fingers, dorsal view (AMS KS63527). 48. Left pedipalpal patella and tibia, dorsal view (AMS KS63527). 49. Penis, ventral view (AMS KS62923). 50. Glans, ventral view (AMS KS62923). 51. Glans, lateral view (AMS KS62923). Scale bars for figs 45–46 = 1 mm; figs 47–49 = 0.5 mm; figs 50–51 = 0.1 mm.