Megalopsalis minima (Kauri, 1954) Kauri, 1954

Taylor, Christopher K., 2013, Further revision of the genus Megalopsalis (Opiliones, Neopilionidae), with the description of seven new species, ZooKeys 328, pp. 59-117 : 65-67

Megalopsalis minima (Kauri, 1954) comb. n. Fig. 3

Spinicrus minimus Kauri, 1954: 7-8, fig. 4 a–b (incorrect original spelling).

Spinicrus minimum Kauri - Taylor 2004: 76 (spelling emended therein by W. Staręga).

Material examined.

1 minor male, Denmark, Western Australia, 34°57'S, 117°21'E, 11 November 1990, A. F. Longbottom, under granite (WAM T72865); 3 minor males, Glenbourne farm, Old Ellensbrook Rd, S of Gracetown, Western Australia, 33°53'S, 115°00'E, 27-28 October 1996, L. Marsh et al., pitfall (WAM T72171, T72184 [2 measured]); 3 major males, ditto, 28-30 June 1997, L. Marsh et al., dry pitfalls, base of cliff (WAM T72167-9; measured); 2 minor males, ditto, 13-15 September 1997, L. Marsh et al., dry pitfall traps (WAM T72176 [measured], T72186); 1 minor male, ditto, 27-29 December 1997, L. Marsh et al., dry pitfalls, site 3 (WAM T72160); 1 minor male, 33°54'28"S, 115°00'49"E, 24-26 October 1998, L. Marsh et al., dry pitfall traps (WAM T72172; measured); 2 minor males, ditto, 33°54'32"S, 115°00'24"E, 24-26 October 1998, L. Marsh et al., dry pitfall traps (WAM T72158); 2 minor males, ditto, 33°54'40"S, 115°00'34"E, 30 October– 1 November 1999, L. Marsh et al., dry pitfall traps (WAM T72144; 1 measured); 1 minor male, ditto, 20-22 October 2001, L. Marsh et al., dry pitfall traps (WAM T72193; measured); 1 minor male, ditto, 33°55'08"S, 115°00'44"E, 20-23 October 2000, L. Marsh et al., dry pitfall traps (WAM T72187; measured).

Diagnosis.

Megalopsalis minima can be distinguished from other members of the Megalopsalis minima -species group by the heavier denticulation on the dorsal prosomal plate (Fig. 3a); the major males can also be distinguished from other species by the proportionately much longer chelicerae (Fig. 3b). It can be distinguished from Megalopsalis porongorupensis by the absence of spines on the pedipalpal femur and patella, and from Megalopsalis suffugiens by the heavily denticulate leg femora (Fig. 3b).

Description.

MAJOR MALE (N = 3). Prosoma length 0.85 (0.78-0.90), width 1.86 (1.74-1.92); total body length 2.37 (2.18-2.56). Dorsal prosomal plate golden brown; median prosomal area strongly denticulate, fewer denticles on margins of anterior and posterior prosomal areas. Ocularium black with row of denticles along edge on each side. Ozopore large, lenticulate. Dorsum of opisthosoma with alternating tan and dark brown mottled with tan stripes, and scattered iridescent white patches. Coxae tan with medium brown distal ends; venter of opisthosoma dark brown medially; tan dusted with black laterally.

Chelicerae. Segment I 5.81 (4.78-7.00), segment II 6.83 (6.10-7.88). Chelicerae golden brown with second segment tan distad; evenly denticulate. Fingers long; mobile finger crescent-shaped (Fig. 3c).

Pedipalps. Femur 0.96 (0.89-1.00), patella 0.44 (0.43-0.46), tibia 0.55 (0.54-0.59), tarsus 1.23 (1.21-1.26). Alternating tan and brown bands; femur without denticles. Femur to proximal part of tibia with longitudinal rows of large setae, distal tibia and tarsus with large setae interspersed among small setae. Inner dorsal distal patella with swelling but no distinct apophysis. Microtrichia on distal end of tibia and tarsus; claw with ventral tooth-row.

Legs. Femora 4.27 (3.82-4.55), 7.51 (6.92-7.92), 3.72 (3.48-3.96), 5.75 (5.33-5.94); patellae 0.87 (0.80-0.98), 0.96 (0.92-1.07), 0.81 (0.76-0.86), 0.95 (0.93-1.00); tibiae 3.96 (3.62-4.28), 8.15 (7.42-8.46), 3.67 (3.44-3.84), 5.79 (5.27-5.98). Femora with strong denticles. Patella I with two longitudinal rows of spines, one on each side; rows continue on tibia, dwindling distalwards. Patellae of other legs only lightly denticulate; tibiae smooth. Tibia II with 7-9 pseudosegments, tibia IV with two pseudosegments.

Penis (Figs 3 d–e). Tendon long; waist in shaft behind bristle groups; left anterior bristle group reduced. Glans short, triangular in ventral view, not strongly flattened distally; dorsal side in line with shaft, evenly convex. Deep pores.

Spiracle. Spines almost entirely absent, residual reticulate bases only towards lateral corner; dense field of lace tubercles at lateral corner.

MINOR MALE (N = 7). Prosoma length 0.73 (0.55-0.83), width 1.82 (1.39-1.68); total body length 1.83 (1.45-2.25). As above, except for following.

Chelicerae. Segment I 0.96 (0.66-2.61), segment II 1.68 (1.27-3.44).

Pedipalps. Femur 0.84 (0.78-0.90), patella 0.37 (0.34-0.39), tibia 0.48 (0.43-0.53), tarsus 1.05 (0.93-1.10).

Legs. Femora 3.48 (3.20-3.70), 6.57 (6.27-6.79), 3.34 (3.00-3.52), 4.79 (4.30-5.00); patellae 0.72 (0.63-0.80), 0.83 (0.77-0.87), 0.72 (0.69-0.76), 0.83 (0.70-0.85); tibiae 3.46 (2.84-3.80), 7.02 (6.33-7.34), 3.26 (2.72-3.52), 4.74 (4.15-5.00). Patella I lightly denticulate, without longitudinal spine rows.

Comments.

Unfortunately, the type specimen(s) of Megalopsalis minima were not available for the present study. This species has been identified based on its original description by Kauri (1954).

Females have been found in association with males of Megalopsalis minima , Megalopsalis porongorupensis and Megalopsalis walpolensis (unpublished observations, specimens in WAM). However, as no distinct morphotypes have been distinguished among the likely females, while the ranges of these species overlap, it has not been possible as yet to determine which females are assignable to which species.