Selkirkiella, BERLAND, 1924

Agnarsson, Ingi, 2004, Morphological phylogeny of cobweb spiders and their relatives (Araneae, Araneoidea, Theridiidae), Zoological Journal of the Linnean Society 141 (4), pp. 447-626 : 476

SELKIRKIELLA BERLAND, 1924

Selkirkiella Berland, 1924 , type species by monotypy Selkirkiella alboguttata Berland, 1924 , not examined.

Removed from synonymy of Anelosimus contra Levi (1972: 536). In addition to S. alboguttata (Berland, 1924) , several former Anelosimus species are transferred and the following new combinations established: S. carelmapuensis (Levi, 1963) , S. luisi (Levi, 1967) , S. magallanes (Levi, 1963) , S. michaelseni (Simon, 1902) , S. purpurea (Nicolet, 1849) , S. ventrosa (Nicolet, 1849) , and S. wellingtoni (Levi, 1967) .

Synapomorphies of Selkirkiella in this study ( S. alboguttata and S. magallanes ) include: conductor enlarged and fan shaped (63, Fig. 67A, C ), conductor heavily ridged (65, Fig. 67C ), TTA apex with small apophysis (82, Fig. 67A, B ), SPR ectally orientated picks absent (153, Fig. 67F ), grooved SPR region (155, Fig. 67F ), and elongate FL spigot (206, Fig. 68E ). Also, characteristically in Selkirkiella the conductor and TTA are strongly compressed together, separated by a narrow seam ( Fig. 67B ). Based on Levi’s (1963, 1967) drawings and descriptions, at least the enlarged and fan shaped conductor, TTA apex apophysis, and TTA and C compressed are universal in Selkirkiella .

Diagnosis

Selkirkiella differs from related pholcommatines by the shape and texture of the conductor, TTA apophysis, TTA and C compressed, lack of ectally orientated SPR, and possibly by mode of egg-sac protection, where a small sheet is woven to cover the egg sac ( Fig. 95E ).

Figures

Figure 67. Selkirkiella sp. A–D, male palp. A, mesial; note knob on the TTA (lowest arrow, 82-1). B, ventral, left arrow shows TTA knob. C, ectal; note two trichobothria on tibia (arrows, 18-2, 19-1). D, subapical; note hood on MA (78-1) and the complementary cymbial hook (Chk, 33-0), on the cymbial margin (35-1). The highly tapered tip (37-1) is a synapomorphic condition for a group within Pholcommatinae (tapered cymbial hook clade). The E is visible tightly wrapped by the C, and the TTA (87-1). E, details of the upward pointed (34-1), tapered, cymbial hook. F, stridulatory area of abdomen; note a pair of SP, and numerous nubbins and ridges (155-1). G, H, S. magallanes. G, prosoma stridulatory ridges. H, pedicel; note slit sensilla (Ss) and nubbins. Scale bars: A–D 100 Mm. E, F, 20 Mm. G, H, 50 Mm.

Figure 68. Selkirkiella magallanes. A, B, D–F, female. A, labium (la) and tips of chelicera. B, cheliceral promarginal teeth. C, epiandrous gland spigots. D, spinnerets. E, PLS. F colulus (arrow). G, epigynum. Scale bars: A, D–G, 100 Mm. B, 20 Mm. C, 50 Mm.

Figure 95. A, typical ‘chicken-wire’ web (225-2) of Synotaxus monoceros, characteristic of this genus (Bartika, Guyana). B, S. waiwai, female guarding egg sac in a simple ‘egg sac web’. (Gunn’s landing, Guyana) C, S. monoceros, female guarding egg sac in an identical web (Bartika, Guyana). D, male of S. monoceros (Bartika, Guyana). E, Selkirkiella luisi (Puyehue, Chile) in an egg-guarding web typical of the genus, superficially similar to Synotaxus. Note that the dense silk mat in Selkirkiella covers the loosely woven egg sac entirely. Enoplognatha ovata is similar (e.g. Nielsen, 1932: 41)