Historical biogeographic reconstruction of the South American Liolaemus boulengeri group (Iguania: Liolaemidae)

The Liolaemus boulengeri group is part of the subgenus Eulaemus, genus Liolaemus. This group is widely distributed in Argentina, Bolivia, Chile, and Paraguay, as well as in the Peruvian Titicaca basin and the coasts of Brazil and Uruguay. Here, we combined the revision of a fossil record of Liolaemus, dated at 20 million years (Myr), with relaxed molecular clock analysis to provide a time-calibrated, molecular-based phylogenetic hypothesis including 90% of the group's known species. We found the Liolaemus boulengeri group (= L. boulengeri section) formed by three main groups, the L. wiegmannii, L. anomalus, and L. darwinii-melanops groups. We performed biogeographic analyses applying Bayesian Binary (BBM), Dispersion-Extinction-Cladogenesis (DEC), and Statistical-Dispersion-Vicariance (S-DIVA) and found that the ancestral area of the L. boulengeri group was likely located in central-west Argentina and reached its current distribution after a series of dispersal and vicariance events. These processes may have been favored by a period of climatic stasis which occurred at the beginning of the group's diversification, around 41 Myr. The congruence of the results of all three biogeographic analyses evidences new hypothetical historical distributions and events which led to the current species distribution of the L. boulengeri group.