Triascutum triascutum Taylor 2025, new combination
Creators: name: Taylor, Christopher K.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Opiliones
Neopilionidae
Triascutum
Triascutum triascutum

description: Triascutum triascutum (Forster, 1944) new combination
Fig. 9
Megalopsalis triascuta Forster, 1944: 189–190, figs 1–3; Taylor, 2011: 44.
Holotype juvenile: WI. Feilding Hills, 1 November 1942, R. Forster, under log (MONZ).
Other material: AK. 1 female, Huia, 20 May–3 June 1981, B. M. May, malaise trap (NZAC); 1 female, Manurewa, 29 May 1943, R. Forster (MONZ); BP. 1 male, 1 female, Papatea, 24 September–19 October 1992, J. S. Dugdale, malaise trap (NZAC); 1 male, Waenga Bush, 16 September 1992, R. C. Henderson, off bases of nikau fronds (MONZ); 1 female, Waiaroho, 17 September–21 October 1992, G. Hall, malaise trap (NZAC); GB. 1 male, Te Piripiri Bay, Lake Waikaremoana, Urewera National Park, 20 March 1997, L. J. Boutin, beech forest, ex sifting litter (MONZ); TO. 1 male, Pureora, Waipapa Reserve, 570 m, 15 December 1983, J. Hutcheson, malaise trap in podocarps (NZAC); 1 male, 1 female, ditto, 27 December 1983, malaise trap in shrublands (NZAC).
Description: As given by Forster (1944), with the following additions: Male chelicerae not enlarged relative to female; teeth on cheliceral fingers with one large tooth towards base of row, remainder evenly serrate; mobile finger without setae. Pedipalp not particularly elongate, length of femur subequal to that of prosoma; patella of both sexes with elongate medial distolateral apophysis, more than twice length of main body of patella, about two-thirds to three-quarters length of tibia, covered with short stout setae, more slender in male than in female; tibia also with small distal apophysis, protruding only slightly past tarsus; plumose setae apparently absent, microtrichia on tarsus only; tarsal claw ventrally rugose; pedipalpal coxa simple, without denticles. Legs elongate but relatively stout; unarmed; microtrichia present on legs from femora to tarsi; tibia II with eight pseudosegments, tibia IV with two. Penis (Fig. 9c–d): Shaft narrow, flattened dorsoventrally; tendon relatively short. Bristle groups medium in length, not extending to dorsal margin of shaft. Glans relatively short but slender, lateral edges in distal half subparallel, slightly curved rightwards, narrow in lateral view. Ovipositor (Fig. 9e): Two seminal receptacles present. Spiracle (Fig. 9b): Curtain of distally anastomosing spines extending over entire spiracle, spines not shortening to tubercles in medial corner.
Comments: Triascutum triascutum can be immediately distinguished from all other Neopilionidae by the very elongate patellar apophysis on the pedipalp, considerably longer than the main body of the patella itself and nearly as long as the adjoining tibia.
This species is widespread in the North Island of New Zealand. To date, I have not identified any features suggesting the presence of more than one species. Though noted to be misplaced in Megalopsalis, M. triascuta was left incertae sedis by Taylor (2011) owing to the juvenile nature of its holotype. Subsequent examination of mature specimens has confirmed its remarkable nature, and both morphological (see below) and molecular (Giribet et al. 2021b) phylogenetic analyses place it in an isolated position from other Neopilionidae. As a result, it is herein transferred to its own genus.
description: Published as part of Taylor, Christopher K., 2025, Further discussion of relationships within Australasian Neopilionidae (Opiliones: Phalangioidea), with description of two new species and eight new genera, pp. 52-82 in Zootaxa 5631 (1) on pages 74-75, DOI: 10.11646/zootaxa.5631.1.2, http://zenodo.org/record/15326621