Web building behavior and the phylogeny of austrochiline spiders

LOPARDO, L.; RAMÍREZ, M. J.; GRISMADO, C. J.; COMPAGNUCCI, L.

JOURNAL OF ARACHNOLOGY

AMER ARACHNOLOGICAL SOC

Lugar: New York; Año: 2004 p. 42 - 54

0161-8202

We report on the natural history and web building behavior of the South American austrochilidsThaida peculiaris and Austrochilus forsteri, relatively basal lineages within Araneomorphae.Species of these two cribellate genera construct large, two-dimensional sheet webs with a funnel retreat.When combing cribellate silk, austrochilids use both fourth legs, like entelegyne spiders, and unlikeHypochilidae and Filistatidae. Furthermore, the alternancy of combing legs IV is determined by the legIII involved in the attachment of a cribellate segment; the leg IV ipsilateral to the leg III that made theattachment will comb the next segment, except for the first segment. This similarity to Entelegynae incombing with both fourth legs contradicts current hypotheses of basal araneomorph relationships andsuggests that the Austrochilidae may be the sister group of entelegyne spiders.