ACKNOWLEDGMENTS
The authors acknowledge the contribution of A. Dondas (Museo Municipal de Ciencias Naturales ‘Lorenzo Scaglia,’ Mar del Plata) for the loan of the specimen under his care. The authors also thank L. Trueb (University of Kansas), R. Maneyro (Universidad de la República, Uruguay), and L. Ambrósio (Universidade de Brasília, Brasil) for providing information or photographs of specimens housed in their respective institutions. The article was greatly improved by suggestions of G. Bever, J. Gardner, and D. Marjanović. Thanks are extended to the Agencia Nacional de Promoción Científica de Argentina (PICT 1985/ 2011) and CONICET for financial support.