Lygophis flavifrenatus Cope, 1862

Type locality. Río Bermejo, province of Formosa, Argentina .

Distribution. Known from Argentina, Brazil, Paraguay, and Uruguay, mostly at the southern portion of the South American open diagonal (Plt. 392A). In Brazil, recorded in southern Atlantic Forest, Pampas Grasslands, and from one record in contact zones between Cerrado and Pantanal (Plt. 392A), at low to intermediate elevations (Plt. 392B). Previous map and taxonomy in Dixon (1989). Observed in the field in open areas, forest, and grassland (Cacciali et al., 2016).