A New Species of Phalotris (Serpentes: Dipsadidae) from the Paraguayan Chaco

Phalotris is a genus of Neotropical snakes with secretive habits that is poorly represented in collections. We describe a new species of Phalotris belonging to the bilineatus group from near Filadelfia in the Dry Chaco of Paraguay. The new species differs from P. lemniscatus and P. spegazzinii by having wider white and black neck collars, a wider black transverse ring in the anal region, and different coloration of the black dorsolateral lines. It differs from P. multipunctatus in the presence of a caudal ring, wider white and black neck collars, and having the entire head black without white marks. In addition, the new species is the only member of the bilineatus group with the black ventral coloration reduced to scattered dots. The new species is described based on three road-killed specimens found since 1995. The new species is currently considered endemic to xerophytic areas of the Paraguayan Chaco. Five species of Phalotris are now known to occur in Paraguay.