Therlinya, Gray & Smith, 2002

Gray, Michael R. & Smith, Helen M., 2002, Therlinya, a new genus of spiders from eastern Australia (Araneae: Amaurobioidea), Records of the Australian Museum 54 (3), pp. 293-293 : 296-299

publication ID

https://doi.org/ 10.3853/j.0067-1975.54.2002.1368

persistent identifier

https://treatment.plazi.org/id/573AD206-1340-FFF3-DA34-FF79FB86C69A

treatment provided by

Carolina

scientific name

Therlinya
status

n.gen.

Therlinya n.gen.

Type species. Therlinya kiah n.sp.

Etymology. The generic name is an Aboriginal word meaning “tongue”. It refers to the shape of the epigynal scape present in most species. The gender is female.

Diagnosis. Therlinya is readily distinguished by its arched, unpatterned carapace. It differs from Stiphidion by the PER being procurved to straight; from Taurongia and Baiami by the possession of a prominent, fleshy median apophysis; from Tartarus by its possession of eyes.

Description. Medium-sized cribellate spiders (CL 2.9–4.8) which build suspended, semi-horizontal sheet webs with shallow retreat tunnel; spiders run underneath sheet. Colour (in alcohol). Cephalothorax cuticle amber coloured, deepest on caput, mouthparts and sternum. Colour pattern ( Fig. 1a,b View Figure 1 ): carapace pallid grey-brown, without obvious patterning; dorsal abdomen with anterior grey/brown stripe (may be indistinct) in paler patch, followed by small cream coloured chevrons (or dots in northern species), reducing in size posteriorly; background colour grey/brown, often lightest anterolaterally & darkest on posterior abdomen; underside dark laterally, then two longitudinal pale cream stripes (sometimes rows of spots) enclosing buff-grey area with two additional often indistinct pale stripes nearer midline; leg femora and tibiae with grey pigment bands, sometimes indistinct to absent in north Queensland species. Feathery, semi-recumbent hairs abundant on abdomen, carapace and legs ( Fig. 2c View Figure 2 ), plus long & short plumose hairs. Long, curved plumose hairs common on leg metatarsi I, II, but absent on tarsi except male tarsus II ( Fig. 2e View Figure 2 ). Carapace ( Fig. 1a,b,d View Figure 1 ) with prominent, broad caput, wider in female, strongly arched, highest at mid-caput ( Fig. 1d View Figure 1 ). Fovea a long slit curving almost halfway down rear slope of carapace. Clypeus 3 × width of an AME. Chilum an undivided, median plate ( Fig. 1f View Figure 1 ). Eyes: Fig. 1e,f View Figure 1 . Eight small, in two rows, facing forward. EGW less than two-thirds (0.6– 0.64×) width of caput. From above AER recurved, PER weakly procurved to straight. AME ALE>PME>PLE or AME>PME=ALE>PLE; AME relatively larger in male. MOQ almost square, slightly narrower anteriorly. Posterior eyes with grate-shaped tapetum. Chelicerae vertical and moderately robust, with boss, fangs with serrate retroventral margins; retromargin with one long, modified seta near base of each fang, numerous modified setae along promargin. Cheliceral tooth pattern—retromargin 2; promargin 3, base of last promarginal tooth extended as a strong carina ( Fig. 1c View Figure 1 ). Maxillae longer than wide, lateral margins weakly undulate to straight, strong linear serrula present. Labium longer than wide or subequal, apically truncate, laterobasally excavated. Sternum longer than wide, shortly pointed between coxae IV. Legs typically 1423 or 1243. Trochanters notched. Spines: Palpal tarsus spinose. Representative leg spination ( T. kiah ). Male (KS58184)—I: femur d1112, p0011; tibia d001, v222, p111, r111; metatarsus d2112, v221, p0101, r0101. II: femur d1202, p0111; tibia d001, v222, p111, r11; metatarsus d2102, v221, p0101, r0101. III: femur d1202, p0111; tibia d11, v212 (112), p11, r11; metatarsus d212, v221, p011, r011. IV: femur d1102, p0001; tibia d101, v112, p11, r11; metatarsus d222, v221, p011, r001. Female (KS58186)—I: femur d1202, p0011; tibia d0010, v220 (222), p111, r101; metatarsus d0202, v221, p1101, r101. II: femur d1102, p0011; tibia d0010, v220, p111 (101), r101; metatarsus d112, v221, p100, r101. III: femur d1102, p0011; tibia d01 (11), v111, p101, r01 (11); metatarsus d212, v221, p11, r11. IV: femur d1102, p0 (0001); tibia d11, v112, p11, r01 (11); metatarsus d222, v211, p011, r001. Three tarsal claws: superior 6–12 teeth, inferior 0–2 teeth. Palpal claw with 8–10 teeth. Claw tufts and scopulae absent; male ventral tarsi with numerous short, inclined hairs. Trichobothria increasing in length distally, in single row on tarsi (6–8) and metatarsi (6–7); two rows on tibia; present on palpal tarsus and tibia. Bothria collariform, proximal plate longitudinally ridged ( Fig. 2a View Figure 2 ). Tarsal organ capsulate, finely ridged longitudinally, with ovoid “keyhole” shaped pore ( Fig. 2b View Figure 2 ); placed distal to trichobothria. Male palp: Figs. 4a,b View Figure 4 , 11a,b View Figure 11 . Trichobothria present on tibia and cymbium. Tibia rather short, with strong prolateral bristles and two retrolateral apophyses: a central-dorsad RTA and a ventrad and apical RVTA, broad-based with a blunt, beaklike apex directed ventrally. Cymbium wide basally with a prominent retrolateral flange and a moderately short, coniform apex. Tegulum with a retrolateral or basal tegular lobe, partially enclosing the S-shaped part of sperm duct; distal loop of sperm duct running anti-clockwise. Embolus origin retrolateral to basal, curving around conductor margin as a long, robust, tapering spine, flattened distally. Conductor large, membraneous, asymmetric T-shape, posterior limb of “T” very short, anterior limb much longer and apically undivided; conductor margin reflected to form a groove for embolus. Tegular window present, placed retrobasally to prolaterally. Median apophysis lobular, a blunt, fleshy process placed centrally above base of conductor. Epigynum typically with a sclerotised, tongueshaped scape ( Figs. 4c–g View Figure 4 ) enclosing a pair of lateral fossae; sometimes scape reduced ( Fig. 16a View Figure 16 ) or absent ( Figs. 5c,d View Figure 5 , 7c View Figure 7 ). Lateral teeth and lobes absent. Internal genitalia ( Fig. 4h View Figure 4 ) simple, with anterolateral copulatory openings leading into broad, proximally flattened copulatory ducts (exceptionally short in T. bellinger ) curving back to a pair of round-ovoid, glandulate spermathecae ( Fig. 13e View Figure 13 ) placed anterior or lateral to epigynal fossae. Tracheal system simple, with four unbranched tracheal tubes confined to the abdomen. Spiracle just anterior to & half as wide as, cribellum. Calamistrum almost half length of metatarsus, subproximal-central, delimited at each end by a retrodorsal spine; absent in male. Spinning organs: Fig. 3a–e View Figure 3 (female).

Cribellum bipartite with two ovoid spinning fields, each about three times as wide as long and well separated by one third of a field width; posterior cribellar margin convex and strongly sclerotised; male cribellum almost as wide as in female with small, non-functional fields. Spinnerets relatively short. ALS and PLS 2-segmented, latter slightly longer; PMS 1-segmented, short; ALS broad with very short apical segment with moderately broad margins; PLS slender with moderately long, conical, apical segment. ALS spigots: 2 major ampullate spigots on mesal side, anterior largest; c. 80 piriform spigots. PMS spigots: two grouped paracribellar bases ectally, each with 7–8 spigots; 1 minor ampullate spigot anteriorly (adjacent to anterior paracribellar base); 1 posterior cylindrical spigot (adjacent to posterior paracribellar base); 8–9 aciniform spigots. PLS spigots: 1 apical “modified PLS spigot” flanked by 3 free paracribellar spigots; 2 cylindrical spigots on mesal side; c. 30 aciniform spigots.

Included species. Therlinya kiah , T. foveolata , T. bellinger , T. horsemanae , T. wiangaree , T. ballata , T. vexillum , T. lambkinae , T. angusta , T. monteithi , T. nasuta .

Distribution. Eastern Australia.

Biology. These cribellate web builders are associated with open and closed moist forest habitats of the eastern highlands and coast. They run on the underside of semihorizontal sheet webs up to 30 cm wide, suspended from funnels leading into burrows 4–10 cm deep in soil banks or logs. The egg sacs are rounded, suspended from the basal burrow roof. A captive female T. kiah (KS58191), sealed within a silk chamber from approximately 1 April to 10 June 1978, produced an egg sac and 224 spiderlings.

Remarks. Therlinya wiangaree , T. ballata and T. vexillum from the Border Ranges region of New South Wales and Queensland form a related group, their T-shaped conductors having very long anterior limbs which also show a trend for increasing distal reflexion.

Cymbium width can vary within species, notably in T. kiah and T. lambkinae . The epigynal scape varies considerably in shape and size between species. Despite some intraspecific variation (e.g., T. kiah : Fig. 4c,e–g View Figure 4 ) it remains a useful structure for species separation. The epigynal scape is absent in two species. Therlinya foveolata has a pit-like, cordate epigynal fossa ( Fig. 5c,d View Figure 5 ) which may be a plesiomorphic state. In T. bellinger the scape appears to be reduced and fused into the central epigynal area ( Fig. 7c View Figure 7 ), a highly derived state.

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Stiphidiidae