“…The points plotted on the distribution map for this species are based on places where the holotype and paratypes were collected: Argentina, province of Formosa, Pilcomayo river (lat 25°22'0"S, long 57°39'0"W); Bolivia, department of Tarija, Samayhuate, Chaco Boreal (lat 21°48'0"S, long 62°55'0.12"W); and Paraguay, department of Presidente Hayes, Boquerón, Fortín Esteros (lat 23°47'0"S, long 61°1'0"W). Jago, 1989. The genera Cephalocoema and Tetanorhynchus have always been placed together as close groups (Bentos-Pereira 2003b, 2007Jago 1989;Mello-Leitão 1939). The species of these genera are certainly very similar in external morphology, and the limits between these groups remained unclear for a long time (Bentos-Pereira 2003b).…”