This species is distinguished from its congeners P. balsanus, P. oaxacae, P. mixtlanensis by having long epiotic processes that extend beyond the epipleural ribs of the first vertebra (vs. short epiotic process not reaching the epipleural ribs of the first vertebra); differs from P. guatemalensis, P. kreiseri by having rows of dark dots along the sides of the body (vs. absence of rows of dark dots in P. guatemalensis, P. kreiseri; differs from P. punctatus by having a dorsoventrally compressed Meckel’s cartilage with a relatively straight ventral edge and a narrow and strongly concave sesamoid articular (vs. dorso-ventrally expanded Meckel’s cartilage with convex ventral edge and a wide and moderately concave sesamoid articular in P. punctatus; differs from P. oaxacae by the number of scales in the lateral series, 33 (vs. 29-31 in P. oaxacae) (Ref. 119416).