TETRAGNATHIDAE MENGE, 1866

Álvarez-Padilla, Fernando & Hormiga, Gustavo, 2011, Morphological and phylogenetic atlas of the orb-weaving spider family Tetragnathidae (Araneae: Araneoidea), Zoological Journal of the Linnean Society 162 (4), pp. 713-879 : 741

publication ID	https://doi.org/ 10.1111/j.1096-3642.2011.00692.x
DOI	https://doi.org/10.5281/zenodo.5492035
persistent identifier	https://treatment.plazi.org/id/7D5E87AD-C075-5519-FC0C-4C1CD28FF9E2
treatment provided by	Valdenar
scientific name	TETRAGNATHIDAE MENGE, 1866
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TETRAGNATHIDAE MENGE, 1866 View in CoL View at ENA

Type genus: Tetragnatha Latreille, 1804 .

Diagnosis: Tetragnathid females can be differentiated from other araneoids by the following combination of features: cheliceral boss present with its cuticle either smooth or similar to the rest of the anterior surface of chelicerae ( Figs 9C View Figure 9 , 23D, E View Figure 23 , 57D View Figure 57 , 101D View Figure 101 ); clypeus more than one AME diameter high; labium trapezoidal and rebordered ( Figs 19G View Figure 19 , 23C View Figure 23 , 47G View Figure 47 ); a flat epigynum, when present (124-0 Figs 79A View Figure 79 , 81D View Figure 81 , 89A View Figure 89 ); ALS piriform spigot bases separated from the spigot shaft by a torus ( Fig. 66B View Figure 66 arrow in insert box points to the torus area wrapping the piriform spigot shaft), absent in Meta and Mollemeta ( Figs 56B View Figure 56 , 82E View Figure 82 ); absence of aciniform spigots on the PMS, present in Azilia and Meta (4-0: Figs 13G View Figure 13 , 56C View Figure 56 , 71A View Figure 71 , 109D View Figure 109 ); and cylindrical spigots on the PLS peripheral in position ( Figs 26D View Figure 26 , 77E View Figure 77 ). Males of Tetragnathidae are distinguished from other araneoids by their large cymbial tarsal organ, larger than the surrounding macrosetal bases; absence of tegular apophyses, except for the conductor (contra Archer, 1951: 4–5); conductor and embolus coiled together; apical position of the embolic division; and by having the embolus connected to the tegulum by a membrane. Tetragnathids differ from nephilids by the absence of cheliceral denticles ( Fig. 93D View Figure 93 ), except in Nanometinae ( Figs 73C View Figure 73 , 88D View Figure 88 ) and by their cylindrical paracymbium ( Fig. 112D View Figure 112 ). The paracymbium of nephilids is more rectangular ( Fig. 138D View Figure 138 ). The webs of nephilids have secondary and tertiary radii ( Figs 6B View Figure 6 , 7A View Figure 7 ), whereas the radii of most tetragnathid webs are undivided ( Figs 4C, F View Figure 4 , 5D View Figure 5 ), and usually have open hubs, few radii, and few spirals of sticky silk (fewer than 20), although exceptions exist, such as the webs of Azilia and Dolichognatha species , which are denser and can have secondary radii ( Fig. 3C, E View Figure 3 ). Secondary radii can also be found in some Glenognatha species (G. Hormiga, unpubl. data). Tetragnathid phylogenetic relationships are discussed in the previous sections. The monophyly of Tetragnathidae is supported by seven morphological synapomorphies: piriform spigot base edges separated from the spigot shaft (2-1: Fig. 66B View Figure 66 ), cymbium tarsal organ diameter larger than the contiguous macrosetae bases (24-1: Fig. 112C View Figure 112 ), oval to spherical tegulum (47-0: Fig. 112A View Figure 112 ), carapace moderately hirsute (98-1: Fig. 62A View Figure 62 ), femora IV mesal surface without basal macrosetae (174-1: Fig. 14H View Figure 14 ); male palpal patella with one macroseta (180-1: Fig. 29F View Figure 29 ); and male palpal tibia length approximately two times the widest point of the tibia (181-1: Fig. 69C View Figure 69 ).