A tale about vipers’ tails: phylogeography of black-tailed rattlesnakes

The phylogenetic relationships among black-tailed rattlesnakes remain poorly understood and some authors indicated that the diversity of this group has been underestimated additional analyses are required to clarify biogeographic patterns throughout its distribution in Mexico. Therefore, aim study was elucidate across their range, identifying relative divergence times main clades reconstructing biogeographical history group. Three partial mitochondrial genes (ND4, cytb ATPase6) one nuclear gene (RAG1) were sequenced infer relationships, through maximum likelihood Bayesian inference-based methods; demographic reconstruction investigated Skyline plot analysis ancestral area carried out considering a framework. We found strong evidence rattlesnakes’ is composed six clades, which agreement with subspecies previously reported. Divergence time estimation origin C. molossus could be traced middle Miocene (~7.71 Mya). Ancestral early events occurred Central Mexico, probably related geological dynamics Trans-Mexican Volcanic Belt. lineage m. oaxacus basal member Furthermore, combination changes Quaternary vegetation may have contributed clades. Our results suggest several within complex potentially recognized as separate species.