Austropurcellia megatanka Jay, Coblens & Boyer

Jay, Katya R., Popkin-Hall, Zachary R., Coblens, Michelle J., Oberski, Jill T., Sharma, Prashant P. & Boyer, Sarah L., 2016, New species of Austropurcellia, cryptic short-range endemic mite harvestmen (Arachnida, Opiliones, Cyphophthalmi) from Australia's Wet Tropics biodiversity hotspot, ZooKeys 586, pp. 37-93 : 49-52

Taxon classification Animalia Opiliones Pettalidae

Austropurcellia megatanka Jay, Coblens & Boyer sp. n. Figs 18, 19, 20, 21, 22, 23

Material examined.

Holotype. Male (QM 102440 [ex MCZ IZ 68951]), Baldy Mountain Road, Herberton Range National Park, 17.287°S, 145.427°E, coll. S. L. Boyer, M. J. Coblens, K. R. Jay and P. P. Sharma 29.v.2014.

Paratypes. 2 males, 1 female, QM 102441 (ex MCZ IZ 68948), same collecting data as holotype. 2 males, 1 female, 3 juveniles, same collecting data as holotype, MCZ IZ 68949, Macalester SEM stubs M27.7, M27.8, M30.2.

Additional material.

1 male, 3 females, Baldy Mountain Road, Herberton Range National Park, 17.267°S, 145.267°E, coll. D. Yeates and D. Cook 25.xi.1985. QM berlesate 683, S 1755, Macalester SEM stubs M23.3, M23.4.

4 males, 1 female, Baldy Mountain, 17.284°S, 145.432°E, coll. G. B. Monteith 10.x.1980, QM S 2281.

1 male, CSIRO Trail (after hut), 17.108°S, 145.629°E, coll. S. L. Boyer, M. J. Coblens, K. R. Jay and P. P. Sharma 29.v.2014, MCZ IZ 68950.

4 juveniles, Mt. Haig, 17.1°S, 145.583°E, coll. Taylor and Feehan 30.vi.1971, ANIC 349.

1 male, 3 females, 5 juveniles, Mt. Haig, Lamb Range, 17.083°S, 145.6°E, coll. G. B. Monteith 25.ii.1997, QM berlesate 918, Macalester SEM stubs M20.11, M20.12.

4 males, 2 females, 22 juveniles, Mt. Tiptree, 17.067°S, 145.617°E, coll. Taylor and Feehan 29.vi.1971, ANIC 345, ANIC 346, ANIC 347, ANIC 348.

Diagnosis.

Distinguished from congeners by an usually wide and long scopula emerging from anterior quarter of male anal plate and easily visible in lateral view. Anal plate is very flat compared to the more rounded anal plates of geographically proximate species such as Austropurcellia tholei and Austropurcellia despectata . Distinctive areas lacking granulation cause ventral sutures to appear fused. Male tarsus IV is fully bisegmented rather than partially bisegmented as in Austropurcellia tholei and Austropurcellia despectata .

Description.

Pettalid with tergite VIII bilobed (Fig. 19). Length of male holotype (Fig. 18) 2.1 mm, width at widest point in posterior third of prosoma 1.2 mm, width at ozophores 0.8 mm. Most of body surface covered in microstructure of tubercles and granules (Fig. 19). Transverse sulci present and granulated (Fig. 19A). Dorsal longitudinal sulcus granulose (Figs 19A, 20A). Granulation medially absent in sternites II-V; area of absent granulation approximately equal to width of gonostome (Fig. 19B).

Ozophores relatively conical, of type III sensu Juberthie (1970) (Figs 19A, 21B). Coxae of legs I and II mobile, coxae of remaining legs fixed. Male coxae II–IV meeting in the midline (Fig. 19B). Male gonostome small, subtriangular, and wider than long (Fig. 19). Spiracles circular and C-shaped with slightly recurved edges, as found in "open circle" type of Giribet and Boyer (2002) (Fig. 21). Anal region of "pettalid type" ( Giribet and Boyer 2002). Anal plate flat and largely ungranulated (Fig. 20B). Long, full scopula emerging from anterior quarter of anal plate and curling into toward posterior quarter of anal plate (Fig. 20B). Anal pore visible (Fig. 20B).

Chelicerae (Fig. 22A) short and relatively robust. Proximal article of chelicerae with dorsal crest, without ventral process. Median article with prominent apodeme. Chela with two types of dentition typical in pettalids (Fig. 22A). Measurements of cheliceral articles of male paratype from proximal to distal (in mm): 0.51, 0.72, 0.25. Palp (Fig. 22B) with prominent ventral process on trochanter. Measurements of palpal articles of male paratype from proximal to distal (in mm): 0.20, 0.25, 0.17, 0.22, 0.24.

Legs with all claws smooth, without ventral dentition or lateral pegs (Fig. 23). All tarsi smooth (Fig. 23). Distinct solea present on ventral surface of tarsus I (Fig. 23A). Metatarsi I and II heavily ornamented on proximal half, with distal half smooth (Fig. 23A, B). Remaining metatarsi with full ornamentation (Fig. 23 C–F). Male tarsus IV fully divided into two tarsomeres (Fig. 23D, E). Adenostyle with relatively robust claw, wide base, and small pore at apex on lateral (external) side (Fig. 23D). Long seta rising from medial (internal) face of adenostyle from below pore to above apex (Fig. 23D, E); very short seta rising from adenostyle base below pore on lateral (external) face (Fig. 23D) (example with adenostyle features labeled, Fig. 5).

Measurements from male paratype of leg articles from proximal to distal (in mm): leg I 0.14, 0.48, 0.20, 0.30, 0.16, 0.39; leg II [trochanter damaged], 0.37, 0.17, 0.26, 0.13, 0.32; leg III [trochanter damaged], 0.30, 0.18, 0.23, 0.15, 0.26; leg IV [trochanter damaged], 0.36, 0.20, 0.28, 0.14, 0.32. Width measurements from male paratype of leg articles from proximal to distal (in mm): leg I [trochanter damaged], 0.15, 0.17, 0.16, 0.14, 0.19; leg II [trochanter damaged], 0.14, 0.16, 0.17, 0.12, 0.13; leg III 0.18, 0.15, 0.15, 0.16, 0.12, 0.11; leg IV 0.16, 0.17, 0.16, 0.18, 0.14, 0.14.

Etymology.

The specific epithet, a noun in apposition, honors a Mitsubishi Pajero four-wheel drive vehicle, nicknamed 'Big Tank,' which made it possible to access various remote localities in the WT, including the type locality of Austropurcellia megatanka sp. n.