Three new species of minute salamanders (Thorius : Plethodontidae) from Guerrero, Mexico, including the report of a novel dental polymorphism in urodeles

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Date Published:

Dec 17


Three new species of minute lungless salamanders of the Mexican genus Thorius (Plethodontidae) are described from montane forests in the Sierra Madre del Sur of Guerrero. Each species is distinguished from congeners by a combination of body size, external morphology, osteology, dental traits, and proteins. Thorius omiltemi and T. grandis are among the largest species within the genus; standard length (SL) approaches or exceeds 30 mm in many adults. Thorius infernalis is much smaller (SL < 19 mm). Adult T. grandis display an extreme, unique sexual dimorphism involving the presence/absence of maxillary teeth and several related features of cranial osteology. Protein (allozyme) data for T. omiltemi and T. grandis reveal substantial levels of genetic differentiation relative to species in Veracruz, Puebla, and Oaxaca. Comparable genetic data are unavailable for T. infernalis, The three species collectively define a broad elevational range, from high elevation T. omiltemi and T. grandis (2200-2700 m and 2495-3360 m, respectively) to lower montane T. infernalis (1140 m), Description of several additional species of plethodontid salamanders from central montane Guerrero underscores the region's rich herpetological diversity, which includes many endemic species of both amphibians and reptiles.


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Last updated on 05/14/2015