Phylogeny of the orb-web building spiders (Araneae, Orbiculariae: Deinopoidea, Araneoidea)

Abstract

This phylogenetic analysis of 31 exemplar taxa treats the 12 families of Araneoidea (Anapidae, Araneidae, Cyatholipidae, Lin)phiidae, Mysmenidae, Nesticidae, Pimoidae, Symphytognathidae, Synotaxidae, Tetragnathidae, Theridiidae, and Theridiosomatidae). The data set comprises 93 characters: 23 from male genitalia, 3 from female genitalia, 18 from céphalothorax morphology, 6 from abdomen morphology, 14 from limb morpholog)', 15 from the spinnerets, and 14 from web architecture and other behaviour. Criteria for tree choice were minimum length parsimony and parsimony under implied weights. The outgroup for Araneoidea is Deinopoidea (Deinopidae and Uloboridae). The preferred shortest tree specifies the relationships ((Uloboridae, Deinopidae) (Araneidae (Tetragnathidae ((Theridiosomatidae (Mysmenidae (Symphytognathidae, Anapidae))) ((Linyphiidae, Pimoidae) ((Theridiidae, Nesticidae) (Cyatholipidae, Synotaxidae))))))). The monophyly of Tetragnathidae (including metines and uephüines), the symphytognathoids, theridiid-nesticid lineage, and Synotaxidae are confirmed. Cyatholipidae are sister to Synotaxidae, not closely related to either the Araneidae or Linyphiidae, as pre\'ionsly suggested. Four new clades are proposed: the cyatholipoids (Cyatholipidae pins Synotaxidae), the 'spineless femur clade' (theridioid lineage plus cyatholipoids), the 'araneoid sheet web builders' (linyphioids plus the spineless femnr clade), and the 'reduced piriform clade' (symphytognathoids plus araneoid sheet web bnüders). The results imply a coherent scenario for web e\olution in which the monophyletic orb gi\es rise to the monophyletic araneoid sheet, which in turn gives rise to the gumfoot web of the theridiid-nesticid lineage. While the spinning complement of single pairs of glands does not change much o\er the e\olution of the gronp, multiple sets of glands are dramatically reduced in number, implying that deri\ed araneoids are incapable of spinning many silk fibers at the same time. INTRODUCTIONThe Araneoidea comprise tlie largest and best Icnown superfamily of spiders. To many obser\'ers, tlie symmetrical orb webs spun by many members of this group epitomize engineering skill and natural beauty. By the same token, the fearsome reputation of the widow spiders {Latrodectus, Theridiidae) for deadly venom and cannibalism during mating symbolizes e\'erything that people dislike about spiders. The 12 families included in this superfamily contain nearly 10 000 described species (Platnick, 1989). Individually, the Linyphiidae and Araneidae rank second and third (after Salticidae) in terms of numbers of described species. The Araneoidea have been the subject of numerous studies and copious speculation regarding the evolution of web building, predatory, and sexual behaviour, much of which could benefit from the organization and perspective that a well supported phylogeny provides.The monophyly of the Araneoidea and of Orbiculariae (Araneoidea + Deinopoidea) has been extensively tested (Coddington, 1986a(Coddington, , 1989(Coddington, , 1990a...

Blueprint for a High-Performance Biomaterial: Full-Length Spider Dragline Silk Genes

“…Black widows, notorious for their neurotoxic venom, are members of the Araneoidea, a superfamily of orb-weaving spiders and their close relatives. Black widows are descended from orb-web weaving ancestors, but they build three-dimensional cobwebs rather than the symmetrical, wagon-wheel shaped orb-web [42]. Despite this difference in web architecture, the breaking strength and extensibility of Latrodectus dragline silk are equal to or higher than those of true orb-weaving spiders [43]–[45].…”

How Did the Spider Cross the River? Behavioral Adaptations for River-Bridging Webs in Caerostris darwini (Araneae: Araneidae)

“…Other simplified features of C. darwini orb webs include few radii (15–30 [23], [25]), broad spiral mesh (5.9–30.5 [23], [25]) and the lack of hub destruction behavior [48]. After finishing spiral construction, C. darwini leave the hub intact, which while typical of species from other orb-weaving families, is unusual in araneids, most of which bite out and replace the hub silk [10], [13], [20], [49].…”

“…The orb web's evolutionary origin defines a single clade, Orbiculariae, a large and diverse group with more than 12.000 species [9]–[12]. Architectural evolution of orb webs through time has resulted in novel web types [9], [13], [14], such as the linyphiid sheetwebs and theridiid cobwebs [10], [15], [16], the deinopid casting web [17], as well as many modifications of the classical orb web [7], [9], [18]–[20]. Because spiders build orb webs using highly stereotypical behaviors that are evolutionarily conserved and phylogenetically informative [13], [20], the evolution of new web architectures are expected to coincide with novel behaviors.…”

The phylogenetic position of Nyctiphruretus acudens, a parareptile from the Permian of Russia

“…However, as many authors (e.g. Griswold et al 1998;Kron and Judd 1997;Prendini 2001;Wiens 1998;Yeates 1995) believe using actual species/genera as terminals in an analysis, even if only a few species are included from each higher taxon, is a superior method to using supraspecific or composite terminals in many respects, a compromise decision was taken here to allow for multistate scoring for each supraspecific terminal if the taxa used to score for that terminal differed in their condition in respect to that character state. For Captorhinidae, scorings were checked against the basal taxa Romeria (Clark and Carroll, 1973) and Concordia (Müller and Reisz, 2005), and for Mesosauridae against Mesosaurus (Modesto, 2006) and Stereosternum (Modesto, 1999).…”