Potamites ecpleopus (Cope, 1875)

Distribution: Distributed in the Amazonia of Brazil, Bolivia, Peru, Ecuador, and Colombia (Ribeiro-Júnior & Amaral 2017). In Colombia in the south portion of the Amazonia region, including the departments of Caquetá, Putumayo, Vaupés, Amazonas, and the eastern foothills of Huila and Cauca (Fig. 4C).

Similar species: This species may be confused with Gelanesaurus spp. and Neusticurus medemi, being differentiated from these two in having six longitudinal rows of tubercles on the dorsum (four rows of keeled enlarged scales forming longitudinal ridges in Gelanesaurus, and small and irregular scales non-forming ridges in N. medemi). See Ávila-Pires (1995) for a more detailed description.

Remarks: Currently, Potamites ecpleopus represents a non-monophyletic clade (Torres-Carvajal et al. 2016; Moravec et al. 2018). Among the variations we observed, we found some specimens with frontonasal scale single (n=10) and others with frontonasal divided (n=7). We also found variation in the presence (n=10) and absence (n=7) of a diamond-shaped azygous scale between prefrontals and frontonasals. Although there are no evident geographical patterns, we observe that most specimens with divided frontonasal have the diamond-shaped scale (70%), while when single, most of them lacked this scale (71%).