Tayshaneta fawcetti, Ledford, Joel, Paquin, Pierre, Cokendolpher, James, Campbell, Josh & Griswold, Charles, 2012

Ledford, Joel, Paquin, Pierre, Cokendolpher, James, Campbell, Josh & Griswold, Charles, 2012, Systematics, conservation and morphology of the spider genus Tayshaneta (Araneae, Leptonetidae) in Central Texas Caves, ZooKeys 167, pp. 1-102 : 26

Tayshaneta fawcetti sp. n. Figs 2B19 A–F31D40A–F 53C60

Leptoneta valverdae Gertsch 1974: 174.

Tayshaneta valverdae (Gertsch, 1974): Ledford et al. 2011.

Type data.

Male holotype from Fawcett’s Cave, Devil’s River State Natural Area, Val Verde County, Texas, 10-November-2009, J. Ledford, J. Kennedy, M. Sanders, T. Garot, K. Wardlaw, 29.90N, 100.91W, (CASC).

Etymology.

The species name is taken in apposition to the type locality and honors the Fawcett family, who owned Fawcett’s Cave and the surrounding Fawcett Ranch prior to its transition as a State Natural Area in 1988.

Notes.

Specimens from Fawcett’s Cave were originally considered by Gertsch (1974) as conspecific with Tayshaneta valverdae based on similarities in somatic morphology and geography. Male specimens from Fawcett’s Cave were unknown at the time and Gertsch (1974) could not evaluate their genitalic morphology. Recent work at Fawcett’s Cave has recovered a series of male and female specimens which are morphologically distinct from Tayshaneta valverdae and appear to not be closely related to other species-groups within Tayshaneta (Figs 4-7).

Other material examined.

USA: Texas: Val Verde County: Fawcett’s Cave, 8mi. W. of Loma Alta, 25-March-1961, M. Tandy, 29.90N, 100.91W, 2 juvs, (AMNH); Fawcett’s Cave, 6mi. N. of Del Rio, 10-April-1968, J. Reddell, 29.90N, 100.91W, 1 ♀, 2 juvs, (AMNH); Fawcett’s Cave, 6mi. N. of Del Rio, 10-November-2009, J. Ledford, J. Kennedy, M. Sanders, T. Garot, K. Wardlaw, 29.90N, 100.91W, 6 ♂, 12 ♀, (TMM).

Diagnosis.

Tayshaneta fawcetti can be separated from all Tayshaneta species, except Tayshaneta emeraldae , Tayshaneta grubbsi , Tayshaneta valverdae and Tayshaneta vidrio , by having the following combination of characters: male palpal tarsus divided apically (TS, Fig. 31D); ventral sclerite short, mesoapically positioned (VS, Fig. 40E); retrolateral sclerite present, pocket-like (RS, Fig. 40E, F). Separated from Tayshaneta fawcetti , Tayshaneta grubbsi , Tayshaneta valverdae and Tayshaneta vidrio by having a distally tapering subquadrate embolus with a distinct basal tooth (E, Fig. 40C, F).

Description.

Male (holotype). Body length 1.56, carapace 0.67 long, 0.58 wide, length 1.15 × width. Carapace pale brown, slightly darker surrounding edges, sparsely setose; eyes reduced, ocular area depigmented (Figs 19 A–C). Legs elongate and thin, femur I 1.83 × carapace length, covered in fine setae and with few scattered spines.Palpal tarsus divided apically (Fig. 31D); retrolateral tibial spine smooth at its base (RTS, Fig. 40D), length 0.38 × tarsus width. Bulb suboval, length 1.8 × width; embolus rectangular, with basal tooth (E, Fig. 40F), length 1.25 × width. Ventral sclerite stout, situated mesoapically (VS, Fig. 40E), retrolateral sclerite pocket-like, weakly invaginated (RS, Figs 40E, F).Abdomen pale brown, without pattern, 0.89 long, 0.67 wide, covered in fine setae.

Variation(n = 2). Total length 1.50-1.56; carapace length 1.15-1.2 × carapace width; length femur I 1.72-1.83 × carapace width.

Female ( Fawcett’s Cave).Body length 1.4, carapace 0.60 long, 0.50 wide, length 1.17 × width. Pigmentation and setation same as for male, except ocular area with a faint dark pattern enclosing the AER (Figs 19 D–F). Legs elongate and thin, femur I 1.6 × carapace length, covered in fine setae and with few scattered spines.Atrium trapezoidal, length 0.73 × width, spermathecae with short twisted stalks and elongate heads (Fig. 53C).Abdomen pale brown, without pattern, 0.80 long, 0.58 wide, covered in fine setae.

Variation(n = 2). Total length 1.25-1.40; carapace length 1.20-1.52 × carapace width; length femur I 1.0-1.4 × carapace width.

Distribution.

Known only from Fawcett’s Cave in the Devil’s River State Natural Area, Val Verde County, Texas (Fig. 60).

Natural History.

Individuals of Tayshaneta fawcetti were photographed during a 2009 expedition to Fawcett’s Cave (Fig. 2B) where they were observed to make fine sheet webs similar to other leptonetid spiders. Male and female pairs were often found in the same web and the egg-sacs were suspended near the web margins. Most specimens were found at the base of the cave’s vertical entrance in twilight under loose rocks and breakdown material.