Theridiosomatidae Simon, 1881

Miller, Jeremy, Griswold, Charles & Yin, Chang, 2009, The symphytognathoid spiders of the Gaoligongshan, Yunnan, China (Araneae: Araneoidea): Systematics and diversity of micro-orbweavers, ZooKeys 11 (11), pp. 9-195 : 20

Family Theridiosomatidae Simon, 1881

Theridiosomatid genera were reviewed by Coddington (1986a). Since then, new species have been described but the systematic structure of the family has remained almost unchanged. The only exceptions are found in Saaristo’s (1996) work, which included the revalidation of Andasta Simon, 1895 , reversing Coddington’s (1986a) synonymy with Theridiosoma O. Pickard-Cambridge, 1879 , and the creation of the new genus Zoma Saaristo, 1996 . Coddington (1986a) noted that some species groups within Theridiosoma might warrant generic status but synonymized Andasta and Theridiosoma pending further study of the phylogenetic relationships within the group. We have no prejudice about whether such a study would support reciprocally monophyletic clades that could be usefully circumscribed as Andasta and Theridiosoma . We are critical of Saaristo’s revalidation of Andasta in a work with narrow geographic focus, rather than as part of a global treatment of the group including a list of species assigned to each genus. A second species of Zoma , including the first known male, is described here. The new genus Coddingtonia is established to accommodate a remarkable theridiosomatid known only from the female.

All theridiosomatids except members of the Neotropical genus Chthonos Coddington, 1986 build orb webs though some are so highly modified as to be hardly recognizable as such. As is typical of members of this genus elsewhere, Gaoligongshan members of Theridiosoma build an orb that is pulled down into a cone by a tension line held by the spider at the hub ( Fig. 7C, D ). Ogulnius in the Gaoligongshan also build orbs that are typical of that genus ( Fig. 7A, B ): the webs have sparse non-sticky elements, lack a frame, have radii attaching directly to the substrate that join to one another irregularly near the hub, and have a sticky spiral winding in an irregular trajectory.

Diagnosis. Theridiosomatidae are small to minute spiders with short to medium length legs and large male palpal bulbs ( Figs 4A , 12A). Synapomorphies for the family proposed by Coddington (1986a) are a pair of pits on the anterior margin of the sternum near the labial base ( Fig. 4D ; character 41, absent from the Neotropical genus Chthonos ), connate spermathecae ( Fig. 11B, D ; character 47), and an elongate dorsal trichobothrium on tibia IV (character 43). These features serve to diagnose the theridiosomatids of the Gaoligongshan, except that the spermathecae of the new genus Coddingtonia are separate ( Fig. 11F ) rather than connate.

Figures

Figure 4. Ogulnius barbandrewsi sp. n. from Guocai He at Fucai. A-D, habitus; E-G, male palp. A, male, lateral; B, female, lateral; C, female, dorsal; D, female, ventral; E, prolateral; F, retrolateral; G, ventral. C: conductor; EA: embolic apophysis; MA: median apophysis; T, tegulum; arrow in D indicates sternal pit.

Figure 7. Webs of theridiosomatid spiders. A, Ogulnius barbandrewsi sp. n. from No. 12 Bridge Camp area, juvenile; B, Ogulnius barbandrewsi sp. n. from Guocai He at Fucai, juvenile, arrow to spider facing away from hub, tensing radial thread; C, D, Theridiosoma diwang sp. n. from Xiao Hei Shan Nature Reserve, female. Arrows indicate location of spider.

Figure 11. A, B, Zoma dibaiyin sp. n. from Pee He; C, D, Wendilgarda muji sp. n. from Xiao Hei Shan Nature Reserve; E, F, Coddingtonia euryopoides sp. n. from Zaotang He at Baihualing village; G-I, Mysmena changouzi sp. n. from from No. 12 Bridge Camp area. A, C, E, G, epigynum, ventral view; B, D, F, I, cleared vulva, dorsal view; H, epigynum, lateral view. Arrow in B indicates lateral pit.