Blakistonia emmottorum, Harrison & Rix & Harvey & Austin, 2018

Harrison, Sophie E., Rix, Michael G., Harvey, Mark S. & Austin, Andrew D., 2018, Systematics of the Australian spiny trapdoor spiders of the genus Blakistonia Hogg (Araneae: Idiopidae), Zootaxa 4518 (1), pp. 1-76 : 36-38

Blakistonia emmottorum , sp. n.

( Fig. 12 A–L)

Type material. AUSTRALIA: Queensland : Holotype male, Noonbah Station, north of Jundah , 24°07’S, 143°11’E, 28 August 1993, hand collected, A.J. Emmott (QMB S29540 ).

Diagnosis. Males of B. emmottorum can be distinguished from those of B. maryae , B. plata , B birksi , B. newtoni , B. hortoni , B. parva , B. maryae , B. olea , B. tariae , B. carnarvon and B. raveni by the prolateral clasping spurs on tibia I, each with raised cuticular bases and bearing multiple terminal peg-like macrosetae ( Fig. 12 G–I); and from those of B. bella , B. pidax , B. tunstilli , B. gemmelli , and B. aurea by the subquadrate (wider than long) eye group ( Fig. 12D ). Females are unknown.

Description. Holotype male (QMB S29540 ). Small idiopid spider (total length 6.0).

Colour (in ethanol; Fig. 12 A–C): Carapace, legs and pedipalp very pale yellow-brown, darker around caput ( Fig. 12A ); sternum, labium and maxillae lighter golden yellow; chelicerae slightly darker yellow-brown ( Fig. 12E, F ); abdomen even paler yellowish brown with faint chevron pattern posteriorly ( Fig. 12A, C .)

Cephalothorax: Carapace 3.2 long, 2.5 wide, 2.0 high, 1.3 times longer than wide; oval ( Fig. 12A ), caput low, ocular area raised ( Fig. 12C ); cuticle smooth, with pits outward from fovea and both sides of caput; fovea slightly procurved; row of setae between fovea and eye group; carapace sparsely setose, with indistinct lines of setae radiating outwards from fovea, concentrated and form fringe on lateral margins; median clump of thickened setae on clypeus ( Fig. 12D ). Length of median clypeus less than 1.0; anterior margin slightly convex. Eye group 0.7 wide, 0.4 long, 0.3 of carapace width; anterior eye row strongly procurved, PLE–PLE/ALE–ALE ratio 0.9; posterior eye row straight; AME about two-thirds of ALE and separated by less than AME diameter; PLE twothirds size of ALE and separated by about ALE diameter; PME pale, just over half size of PLE, and separated from PLE by less than its own diameter ( Fig. 12D ). Labium without cuspules ( Fig. 12F ). Sternum 2.0 long, 1.3 wide, evenly setose. Maxillae with ca. 6 cuspules on both sides ( Fig. 12E, F ).

Legs: diffusely setose; tarsi I, II ventrally swollen; tarsi I, II weakly scopulate ( Fig. 12 G–I). Paired tarsal claws: leg I p4 (2 large, 2 small) r4 (2 large, 2 small); leg II p5 (2 large, 3 small), r4 (2 large, 2 small); leg III p4 (3 large, 1 small), r4 (2 large, 2 small); leg IV p8 (7 large, 1 small, r4 (2 large, 2 small).

Spination: Tibia I with prolateral clasping spurs, distal-most spur with 2 terminal peg-like macrosetae, proximal-most with 3 terminal peg-like macrosetae ( Fig. 12 G–I). Leg II: metatarsus p1, r5. Leg III: tibia p1, r1; metatarsus p4, r10; tarsus p1, r1. Leg IV: metatarsus p11, r7; tarsus p3, r4.

Leg and pedipalp measurements: Length of legs IV> II> I> III. Leg I: femur 3.3, patella 1.5, tibia 2.5, metatarsus 2.2, tarsus 1.5, total = 11.0. Leg II: femur 3.0, patella 1.0, tibia 2.2, metatarsus 3.0, tarsus 1.1, total = 10.3. Leg III: femur 2.3, patella 1.0, tibia 2.0, metatarsus 2.3, tarsus 1.4, total = 9.0. Leg IV (right): femur 3.8, patella 1.4, tibia 3.4, metatarsus 3.6, tarsus 1.9, total = 14.1. Pedipalp: femur 1.7, patella 1.0, tibia 1.6, tarsus 0.8, total = 5.1.

Pedipalp: Femur with thickened dorsal setae; tibia short and swollen, RTA short, stout, pointed, covered in short, dense spinules that continue for ca. half distance between base of apophysis and distal tibia, becoming more sparse toward distal tibia; long, erect setae ventrally on tibia; bulb uniform, globular; embolus simple, slender, tapering, twisted, slightly longer than bulb; cymbium with sparse rows of short spinules, becoming longer and denser distally ( Fig. 12 J–L).

Abdomen: Setose, oval, dorsal sigilla not evident; 3.0 long, 2.0 wide ( Fig. 12A ).

Variation: None.

Etymology. This species is named in honour of Angus and Karen Emmott, the owners of Noonbah Station and the collectors of the only known specimen of this species.

Distribution. Blakistonia emmottorum is known only from Noonbah Station in central Queensland ( Fig. 34 ).

Remarks. The specimen was found in a passage between houses at Noonbah Station, in August during rain.

Figures

FIGURE 12. Blakistonia emmottorum sp. n., holotype male (QMB S29540): A, habitus, dorsal view; B, habitus, ventral view; C, habitus, lateral view; D, eye group, dorsal view; E, sternum, ventral view; F, maxillae and labium, ventral view; G, left leg I, prolateral view; H, left leg I, clasping spurs, prolateral view; I, left leg I, ventral view; J, left pedipalp, prolateral view; K, left pedipalp, retrolateral view; L, left pedipalp, proventral view. Scale bars = 5 mm (A), 2 mm (G, J).

FIGURE 34. Distribution of Blakistonia species: B. emmottorum sp. n. (black square), B. raveni sp. n. (black triangle), B. carnarvon sp. n. (black circle), and B. plata sp. n. (white circle).