Species of the genus Lithobates are difficult to identify, especially on the ‘Rana pipiens’ complex, because the morphological differences among the species are often subtle. In this study, we used 12S ribosomal RNA gene partial sequences to identify specimens of leopard frogs from some new localities (not sampled on previous studies) of the Southern Mexican Plateau, to carry out a phylogenetic analysis, and also a morphometric analysis of some morphological features were analyzed to evaluate their morphological variation. A phylogenetic analysis using partial sequences of 12S rDNA mitochondrial gene for 31 samples was carried out using Bayesian Inference, Maximum Parsimony, and Maximum Likelihood. In addition, 20 morphological lineal measurements from 97 specimens were analyzed by principal component analysis (PCA) to evaluate if the frogs studied are conspecific. Partial sequences of the 12S rDNA obtained from frogs distributed in the Southern Mexican Plateau show two haplotypes with a divergence of 0.4%. Phylogenetic hypothesis shows an exclusive group with a previous sequence of Lithobates montezumae. The PCA indicates that variables are not linearly correlated and specimens belong to a single group. Evidence found, let us consider that specimens studied belong to one species of the Lithobates montezumae subgroup, distributed principally in the Southern Mexican Plateau.

硬脂酸杆菌属的种类很难鉴定，尤其是在'Rana pipiens'上复杂，因为物种之间的形态差异通常很细微。在这项研究中，我们使用12S核糖体RNA基因部分序列从南部墨西哥高原的一些新地方（以前的研究中未采样）中鉴定出豹蛙的标本，进行了系统发育分析，并对某些形态进行了形态计量分析分析特征以评估其形态变化。使用贝叶斯推断，最大简约性和最大似然性，对31个样品使用12S rDNA线粒体基因的部分序列进行了系统发育分析。此外，通过主成分分析（PCA）对来自97个标本的20个形态学线性测量值进行了分析，以评估研究的青蛙是否具有同种性。从分布在墨西哥南部高原的青蛙获得的12S rDNA的部分序列显示出两种单倍型，差异为0.4％。系统发育假说显示了一个排他性的群体，其先前的序列蒙特泽玛石矿。PCA指示变量不是线性相关的，并且标本属于单个组。找到的证据让我们考虑到，所研究的标本属于褐藻岩（Lithobates montezumae）亚组的一种，主要分布在墨西哥南部高原。