title: The female genital morphology of the orb weaving spider genus Agriognatha (Araneae, Tetragnathidae).
abstract: The female genital morphology of the spiders in the araneoid genus Agriognatha (Tetragnathidae) is described and illustrated. The female genitalia of Agriognatha is characterized by a strong reduction of the sperm storage organs (spermathecae) and by the presence of a specialized distal compartment of the median membranous chamber that functions as a sperm storage organ (the posterior sac). The genital morphology of Agriognatha species is unique among Tetragnathidae and it provides robust synapomorphic evidence for the monophyly of genus. We discuss the phylogenetic implications of these new findings for the placement and monophyly of Agriognatha and for the monophyly of Tetragnathinae.
authors.affiliation: Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA. dimitard@gwu.edu
authors.forename: Dimitar
authors.initials: D
authors.lastname: Dimitrov
authors.forename: Fernando
authors.initials: F
authors.lastname: Alvarez-Padilla
authors.forename: Gustavo
authors.initials: G
authors.lastname: Hormiga
mesh_terms: D000818:Animals; D005260:Female; D005836:Genitalia, Female / Q000648:ultrastructure*; D010802:Phylogeny; D013112:Spiders / Q000033:anatomy & histology* / Q000145:classification