Austropurcellia riedeli Jay, Oberski & 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 : 60-65

Taxon classification Animalia Opiliones Pettalidae

Austropurcellia riedeli Jay, Oberski & Boyer sp. n. Figs 36, 37, 38, 39, 40, 41

Material examined.

Holotype. Male (QM 102448), Rossville, Bloomfield (sample 2B, AR2), 15.792°S, 145.302°E, coll. Alex Riedel 1.v.2014.

Paratype. 1 female, Rossville, Bloomfield (sample 2B, AR2), 15.792°S, 145.302°E, coll. Alex Riedel 1.v.2014, QM 102449.

Additional material.

1 male, 2 females, Rossville, Bloomfield (sample 2, AR1), 15.792°S, 145.302°E, coll. Alex Riedel 29.iv.2014, MCZ IZ 69026, Macalester SEM stubs M30.13, M30.14, M30.15.

Diagnosis.

Distinguished from congeners by flat anal plate granulated anteriorly, with very short and round scopula emerging from posterior third of plate. Lobes of tergites VIII and IX rounded and prominent in dorsal view; absence of granulation in junction of the anal plate, the lobes of tergite VIII, and the dorsal scutum. Closely resembles Austropurcellia finniganensis , but distinguished by its larger body size (0.4 mm longer, 0.2 mm wider).

Description.

Pettalid with tergite VIII bilobed (Fig. 37). Posterior margin of dorsal scutum curves ventrally (Fig. 36C). Length of male holotype (Fig. 36) 2.5 mm, width at widest point in posterior third of prosoma 1.4 mm, width at ozophores 1.0 mm. Most of body surface covered in microstructure of tubercles and granules (Fig. 37). Transverse sulci present and distinct by lack of granulation (Figs 36A, 37A). Dorsal longitudinal sulcus lacking granulation, with adjacent flanking granules oriented parallel to dorsal longitudinal sulcus (Figs 36A, 37A). Anterior edge of sternites IV and V lacking granulation medially (Fig. 37B).

Ozophores relatively conical, of type III sensu Juberthie (1970) (Fig. 37A, 39B). Coxae of legs I and II mobile; coxae of remaining legs fixed. Male coxae II-IV meeting in the midline (Fig. 37B). Male gonostome small, subtriangular, wider than long (Fig. 37B). Spiracles circular and C-shaped with slightly recurved edges (Fig. 39A), as found in "open circle" type of Giribet and Boyer (2002). Anal region of "pettalid type" ( Giribet and Boyer 2002). Anal plate flat, posteriorly convex, with anterior granulation (Fig. 38B). Short, round scopula extruding from circular area on posterior third of anal plate and extending just past posterior margin of anal plate (Fig. 38B). Orientation of scopula obscures anal pores, which are not visible (Fig. 38B).

Chelicerae (Fig. 40A) 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. 40A). Measurements of cheliceral articles of male paratype from proximal to distal (in mm): 0.81, 1.02, 0.33. Palp (Fig. 40B) with prominent ventral process on trochanter. Measurements from palpal articles of male paratype from proximal to distal (in mm): 0.22, 0.39, 0.21, 0.35, 0.29.

Legs with all claws smooth, without ventral dentition or lateral pegs (Fig. 41). All tarsi smooth (Fig. 41). Distinct solea present on ventral surface of tarsus I (Fig. 41A). Metatarsi I and II heavily ornamented on proximal half, with distal half smooth (Fig. 40A, B). Remaining metatarsi with full ornamentation (Fig. 41 C–F). Male tarsus IV fully divided into two tarsomeres (Fig. 41D, E). Adenostyle with relatively robust, pointed claw curving distally, wider base, and small pore at apex on lateral (external) side (Fig. 41D). Long seta rising from medial (internal) face of adenostyle from below pore to above apex (Fig. 41D, E); very short seta rising from adenostyle base below pore on lateral (external) face (Fig. 41D) (example with adenostyle features labeled, Fig. 5).

Measurements from male paratype of leg articles from proximal to distal (in mm): leg I 0.28, 0.64, 0.25, 0.48, 0.23, 0.46; leg II 0.22, 0.49, 0.25, 0.39, 0.16, 0.42; leg III 0.17, 0.42, 0.25, 0.35, 0.20, 0.39; leg IV 0.22, 0.61, 0.29, 0.44, 0.25, 0.41. Width measurements from male paratype of leg articles from proximal to distal (in mm): leg I 0.23, 0.21, 0.21, 0.20, 0.17, 0.23; leg II 0.21, 0.19, 0.19, 0.20, 0.15, 0.15; leg III 0.22, 0.21, 0.20, 0.20, 0.15, 0.16; leg IV 0.25, 0.23, 0.24, 0.25, 0.21, 0.20.

Etymology.

This species is named after Alex Riedel, the German entomologist who provided us with several collections of animals from key localities, including Mount Finnigan.