Negragrion Sagma Gen.N. And Sp.N. From South America With A Morphological Phylogeny Of The New World Ischnurinae (Odonata: Zygoptera: Coenagrionidae)

A new coenagrionid genus, Negragrion, is described for N. sagma sp.n. found in Argentina and Brazil (Holotype and allotype, pair in tandem. Argentina: Corrientes: Santo Tome, arroyo Ita Cua sobre RP 94, 28 degrees 26'48.30 '' S 56 degrees 00'3311 '' W, 24.ii.2003, Muzon & Pessacq coll., MLP). The new genus is characterized by the shape of male cerci (decumbent from base; saddle-shaped; in lateral view with an acute a pophysis directed dorsally located at 0.3 from base). The presence of a vulvar spine on 58 of females places this genus within Ischnurinae. A cladistics analysis using morphological data was carried out to determine its phylogenetic position. Negragrion gen.n. is recovered within the Glade 4 as the sister group of the Glade (Acanthallagma Acanthagrion (Oxyagrion, Fluminagrion)).