Lateral (A–C), dorsal (D–F), and ventral (G–I) views of the heads of representative specimens from both morphotypes. The left column (A, D, G) shows a B-morphotype specimen from the Monte of Plains and Plateaus (Rio Negro province, MLP.R 5313). The middle column (B, E, H) features a B-morphotype specimen from the Pampa (Buenos Aires province, MLP.R 6039). The right column (C, F, I) presents an A-morphotype specimen from the Humid Chaco (Corrientes province, MLP.R 5449, holotype). Arrows and asterisks highlight character states (see File S2). Photographs A–F include a line-drawing diagram highlighting in grey the scales involved in each character state, as indicated by arrows and asterisks in the corresponding images. Scale bars = 5 mm.