An integrative approach to elucidate the taxonomic status of five species of Phymaturus Gravenhorst, 1837 (Squamata: Liolaemidae) from northwestern Patagonia, Argentina

Abstract

The lizard genus Phymaturus comprises two reciprocally monophyletic clades: Phymaturus palluma and Phymaturus patagonicus. Species belonging to the P. patagonicus clade occur in extra-Andean Patagonia, and some of them remain with unresolved phylogenetic relationships after studies based on morphological and nuclear and mitochondrial DNA (mtDNA) evidence. Here, we elucidate the taxonomic status of five putative species originally described according to morphotypes based upon morphometric and meristic characteristics and dorsal colour pattern: Phymaturus agilis, Phymaturus excelsus, Phymaturus manuelae, Phymaturus spectabilis and Phymaturus spurcus. We amplified a 657 bp fragment of COI mtDNA from 23 individuals and a 2708 bp fragment of cytochrome b, ND1, ND2 and eight transfer RNAs from another 114 individuals. We found strong support for two reciprocally monophyletic genetic lineages: a small clade for P. manuelae and a large polytomic clade for the rest of the presumed species. A haplotype network analysis unveiled a genetic structure for lineages in the large clade, suggesting that morphological differences are a consequence of population divergence. To complement the molecular analyses, we estimated morphotype proportions in populations and estimated morph heritability with the regression of offspring on females bearing species-typical phenotypes. Our results indicate that P. agilis, P. excelsus, P. spectabilis and P. spurcus compose a single highly structured species.