Tylorida SIMON 1894

TYLORIDA SIMON, 1894 (FIGS 5E, 114–118)

Type species: Tylorida striata (Thorell, 1877). Type specimen and depository museum unknown.

Diagnosis: Tylorida species differ from other tetragnathids in the following combination of characters: femora IV with smooth trichobothrial shaft (Fig. 115F); copulatory and fertilization ducts running parallel before entering the spermathecae (Fig. 116C); tegulum ventrally swollen (Fig. 117B); cymbial dorsobasal process shorter than half the cymbial width and perpendicular to the cymbium longitudinal axis (Fig. 117A, F). The following description is based on our study of Tylorida striata.

Description: Female: body length c. 10.0 mm. Femora IV trichobothrial shaft not branched, shorter than half the femur length (Fig. 115F). Ocular area lower than carapace lateral margins (Fig. 115B, D). Labium trapezoidal, wider than long, and rebordered. Sternum longer than wide (Fig. 115E). Anterior surface of chelicerae smooth; boss present (Fig. 115B). Secondary eyes with canoe-shaped tapetum. Eyes subequal in size, lateral eyes juxtaposed, and on a tubercle. Clypeus almost 1.5 times the AME diameter. Abdomen anteriorly projected and covered with silver guanine patches that form longitudinal lines (Tanikawa, 2005: figs 1, 2). Booklung cuticle smooth. Tracheal spiracle near the spinnerets. Median tracheae not ramified, longer than half the lateral tracheae length (Fig. 114A, C, D). ALS with an extensive field of piriform spigots (Fig. 114B). PMS with three aciniform spigots between the cylindrical and minor ampullate silk gland spigots but without any aciniform spigots over the anterior surface (Fig. 114E). PLS with c. 20 aciniform spigots arranged in roughly parallel lines; distal end of aggregate spigots separated from tip of the flagelliform spigot (Fig. 114G). Epigynal plate flat, copulatory openings ventrally orientated (Fig. 116A). Spermathecae walls weakly sclerotized. Copulatory and fertilization ducts coiled, longer than the spermatheca length and cuticle well sclerotized (Figs 116F, 118D). Accessory gland ductiles concentrated near the duct junction, accessory glands acorn-shaped and in individual pits (Fig. 116B, E).

Male: size and somatic morphology similar to that of the female (Fig. 115C, D). PLS triplet reduced to nubbins. Epiandrous plate well sclerotized, fusules immersed in a transverse groove with their bases wider than fusule shaft (Fig. 114F). Palpal patella without macrosetae. Palpal femora very long, more than four times its width. Tibia length slightly more

802 F. ÁLVAREZ-PADILLA and G. HORMIGA than one times its width (Fig. 117D). Paracymbium shorter than half the cymbium length, curved and with the distal margin swollen (Fig. 117F). Subtegulum ectally displaced (Fig. 117C). Conductor edges well sclerotized, median sections rigid but weakly sclerotized. Conductor-tegulum attachment membranous (Figs 117E, 118C). Embolus base rectangular, longer than wide (Fig. 118C). Embolus flexible and weakly sclerotized. Sperm duct with more than five coils (Fig. 118A, B).

Natural history: There are nine described species of Tylorida, all from the Australasian region, with some species extending to western South Africa and Cameroon (Chrysanthus, 1975; Davies, 1988; Zhu et al., 2003). Tylorida striata builds horizontal webs with c. 20 spiral switchbacks, c. 15 radii, an open hub, and an open sector (Fig. 5E). The reproductive behaviour of Tylorida ventralis (Thorell, 1877) has been recently documented (Preston-Mafham & Cahill, 2000). The web building behaviour of T. striata was described by Eberhard (1982).

Taxonomy: The monophyly of Tylorida remains to be tested. The Chinese Tylorida species were recently treated by Zhu et al. (2002) and the Japanese species by Tanikawa (2005). A previous phylogenetic analysis proposed T. striata as sister to Mesida (Fig. 141B; Tanikawa, 2001). The sister taxa relationships of Tylorida with other Leucauginae genera are unresolved by the data set of morphology plus behaviour (Fig. 143A, B). In the total evidence analysis Tylorida is sister to Orsinome (Fig. 144).