Taphiassa castanea Rix & Harvey, 2010

Rix, Michael & Harvey, Mark, 2010, The spider family Micropholcommatidae (Arachnida: Araneae: Araneoidea): a relimitation and revision at the generic level, ZooKeys 36 (36), pp. 1-321 : 85-86

Taphiassa castanea Rix & Harvey , sp. n.

urn:lsid:zoobank.org:act:032497CC-BBF5-49F1-A91F-CD2F88D8F4D1

Figs 152C, 163–164, 169C, 170–175

Type material. Holotype male: Cuckoo Falls , near Scottsdale, Tasmania, Australia, beating ferns, 41°14'13"S, 147°36'49"E, 26.IV.2006, M. Rix ( TMAG).

Paratypes: Allotype female, same data as holotype ( TMAG); 5 males, same data as holotype ( WAM T94478); 1 male, same data as holotype ( WAM T80024 DNA-MPE) .

Other material examined. AUSTRALIA: Tasmania: Liffey Falls , 14.V.1953, V. Hickman, 1♁, 1♀ ( AMS KS49192 ) ; track off Mount Barrow Road , 780 m, pyrethrum fogging tree ferns, 15–17.II.1980, A. Newton, M. Thayer, 1♀ ( AMNH) ; Mount Wellington, Cascades , 10.IV.1961, V. Hickman, 1♁ ( AMS KS30732 ) ; Mount Wellington, ‘ Fern Tree’ , beating low-growing ferns, 42°55'19"S, 147°15'36"E, 28.IV.2006, M. Rix, 5♁, 1♀ ( WAM T94475 SEM♁ ♀) ; Mt Wellington, Lenah Valley track from ‘ The Springs’ carpark, sifting moss and leaf litter, 27.IV.2007, M. Rix, 1♀ ( WAM T94474) ; 60 km S. of Smithton on Sumac Road , mixed litter, 3.III.1977, J. Kethley, 1♀ ( FMC) ; south-western Tasmania , 42°37'S, 145°45'E, 9.II.1976, C. Howard et al., 1♀ ( AMS KS26237 ) .

Etymology. The specific epithet is derived from the Latin ‘castaneus’, meaning ‘of the colour of chestnuts, brown’ ( Brown 1956), and refers to the brown carapace colouration of this species.

Diagnosis. Males of Taphiassa castanea can be distinguished from all other described congeners by the small body size (carapace length <0.60), and by the oval profile of the tegulum in ventral view (Fig. 164A). Females can be distinguished from all other described congeners by the small body size (carapace length <0.60) and by the distinctive shape of the receptacula (Fig. 169C). Both sexes can also be recognised by the Tasmanian distribution.

Description. Holotype male: Total length 1.13. Carapace 0.55 long, 0.43 wide. Abdomen 0.64 long, 0.61 wide. Leg I femur 0.58. Cephalothorax, abdominal sclerites dark brown; legs dark tan-yellow; abdomen dark olive, with slightly darker markings mesally and laterally. Carapace raised anteriorly, fused to sternum via pleural sclerites, with circular sclerotic rim around petiole; dorsal surface of pars cephalica slightly convex in lateral view; carapace and sternum heavily punctate. Eight subequal eyes present on anterior margin of pars cephalica; PME separated by slightly less than half their own diameter. Chelicerae without bulging anterior projections; promargin without peg teeth. Legs relatively short (leg I femur-carapace ratio 1.05); macrosetae absent. Abdomen globose, covered with hair-like setae, each seta projecting from small sclerotic spot; dorsal scute and lateral sclerotic strips absent. Pedipalpal patella with retrolaterally-directed, hooked lRPA and strongly recurved distal apophysis; bulb oval in profile, with posteriorly-bulging subtegulum; tegulum smooth, oval in profile, with curved ETR; embolus long (length> 5× width), curving distally (Fig. 164).

Allotype female: Total length 1.25. Carapace 0.53 long, 0.46 wide. Abdomen 0.72 long, 0.65 wide. Leg I femur 0.58. Cephalothorax, abdominal sclerites dark brown; legs dark tan-yellow; abdomen dark grey. Carapace raised anteriorly, fused to sternum via pleural sclerites, with circular sclerotic rim around petiole; dorsal surface of pars cephalica slightly convex in lateral view; carapace and sternum heavily punctate. Eight subequal eyes present on anterior margin of pars cephalica; PME separated by slightly less than half their own diameter. Chelicerae without bulging anterior projections; promargin without peg teeth. Legs relatively short (leg I femur-carapace ratio 1.09); macrosetae absent; superior claws on legs I–II strongly pectinate. Abdomen globose, slightly shrunken, covered with hair-like setae, each seta projecting from small sclerotic spot; dorsal scute and lateral sclerotic strips absent. Pedipalp very small, reduced to a vestigial nubbin. External epigyne indistinct (Fig. 163D); spermathecae globular, oval in profile; insemination ducts short; fertilisation ducts simple, curved (Fig. 169C).

Distribution. Known only from Tasmania.

Remarks. Taphiassa castanea is a common species in Tasmania, where it can be found living under low ferns in temperate rainforest habitats, sometimes in direct sympatry with another species of Taphiassa very similar to T. robertsi . It is most similar to T. globosa and several other undescribed species from mainland Australia. This species was included in the molecular phylogenetic analysis of Rix et al. (2008) as “ Parapua sp. TAS”.