Accensus brevicrus, Taylor, 2025

Accensus brevicrus new species

Fig. 5 View FIGURE 5

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Etymology: Latin, noun in apposition, from brevis, short, and crus, leg.

Holotype: CO. Male, Carrick Range, Watts Rock , 1295 m, pit traps, J. C. Watt, 13–15 Feb 1983 ( NZAC).

Specimens: 3 males, 1 juvenile, as for holotype ( NZAC) .

Description: Male ( Fig. 5 View FIGURE 5 ): Prosoma length 0.4–0.6, prosoma width 1.1–1.3, body length 1.8–2.2. Dorsum unarmed, opisthosoma not sclerotized. Dorsal prosomal plate yellow tan, with purple mottling laterally and in front of ocularium. Ocularium low in lateral view. Ozopores small and rounded; slightly but not prominently raised. Mouthparts cream-coloured. Coxae cream-coloured with medium brown patches distally, and with scattered black setae. Dorsum and venter of opisthosoma cream-coloured with transverse stripes of purple mottling; no prominent setae present. Chelicerae ( Fig. 5b View FIGURE 5 ): Segment I 0.5–0.6, segment II 1.0–1.1. Relatively short, not extending far above dorsum of body; both segments unarmed. First segment cream-coloured; second segment light brown for most of length, cream-coloured distally. Second segment inflated, more so dorsoventrally than frontolaterally. Fingers slender, relatively straight, angled mesad in frontal view; mobile finger not bearing setae, closing tightly against fixed finger. Pedipalps ( Fig. 5c View FIGURE 5 ): Femur 0.4–0.5, patella 0.3, tibia 0.4, tarsus 0.7–0.8. Inner margin of coxa without protruding flange, unarmed; base of coxa without tubercles. Entire pedipalp unarmed. Femur medium brown except cream-coloured proximally and distally; patella, tibia and tarsus each light brown basally, cream-coloured distally. Patella mediodistally rounded, but without distinct apophysis; no dense setation on patella and tibia, pedipalp with sparse black setae throughout. Microtrichia present on distal half of tibia and entire length of tarsus. Tarsal claw without ventral tooth-comb. Legs: Leg I femur 0.9–1.0, patella 0.4, tibia 0.9–1.0; leg II femur 2.0, patella 0.6, tibia 2.3; leg III femur 0.9, patella 0.3, tibia 0.8–0.9; leg IV femur 1.6–1.7, patella 0.4–0.5, tibia 1.3–1.5. Relatively short and stout; all segments unarmed; microtrichia present on patellae, tibiae and tarsi. Banded cream and light brown. Tibia II with six pseudosegments; tibia IV undivided. Penis ( Fig 5d, e View FIGURE 5 ): Shaft relatively broad and flat, wider than glans. Anterior bristle groups quite short; posterior bristle groups longer, relatively slender. Glans only about as long as wide, subquadrate in ventral view with distal triangular finger-like process undershooting stylus.

Comments: This remarkable species is immediately distinguishable from any other New Zealand neopilionid by its short legs but relatively unsclerotised dorsum. The only other Neopilionidae with such short legs relative to body size are the New Zealand species Monoscutum titirangiense , Acihasta salebrosa , and Templar incongruens , and the Australian genus Australiscutum . The New Zealand species are more heavily sclerotised than Accensus brevicrus , with raised tubercles on the dorsum in Monoscutum and Templar , and spine-like lateral processes on the opisthosoma in Acihasta . Australiscutum also bears a nodular dorsum, and male chelicerae are heavily denticulate. Accensus also exhibits a distinctive genital morphology, with the glans having an acute apex that extends well past the insertion point of the stylus.