A phylogeny of Mexican Ambystoma salamanders (Caudata: Ambystomatidae) from larval characters.

摘要

A phylogeny of Mexican Ambystoma salamanders was constructed using larval morphology. Characters were scored for 19 ambystomatid species from Mexico and North America. Twenty-five continuous characters came from external measurements of cranial and branchial features and ratios of measurements. Twenty-six categorical characters were scored from internal and external larval, branchial, and cranial features, as well as overall color and adult life history. Cladograms constructed from individual character matrices lack major resolution beyond individual species level. The consensus cladogram did not resolve the majority of species, and was similar to consensus results from previous cladistic analysis based on molecular characters. Convergent morphology is evident in characters of geographically distant members of the Glade. However, species determination was possible for all examined taxa. Neoteny is widespread in the A. tigrinum complex and, as an isolating mechanism, may be the main driver of speciation in the complex.