Spiny tails and clades: A fully sampled phylogeny of hoplocercine lizards (Iguanidae/Hoplocercinae) and its taxonomic and nomenclatural implications

Hoplocercine lizards (Enyalioides, Morunasaurus, and Hoplocercus) form a clade of ca. 20 currently recognized species. The phylogenetic relationships among hoplocercine lizards, whose members exhibit striking differences in morphology (e.g., spiny vs. non-spiny tails), have not been clearly resolved by previous molecular phylogenetic studies. We generated a considerably larger dataset including 130 new DNA sequences from one mitochondrial and four nuclear loci for all named and two unnamed species of Hoplocercinae. We analyzed the data under concatenated maximum likelihood (RAxML) and Bayesian (MrBayes) as well as summary coalescent (ASTRAL) approaches. While our phylogenetic hypotheses strongly supported the monophyly of Hoplocercinae, neither Enyalioides nor Morunasaurus was supported as monophyletic. Instead, M. groi was inferred with strong support to form a clade with E. heterolepis and E. laticeps. This clade was in turn the sister taxon to other species of Morunasaurus (M. annularis, M. peruvianus). The remaining species of Enyalioides formed a separate clade with a basal split between western (3 species) and eastern (13 species) subclades. Tree topology tests rejected the monophyly of Enyalioides but failed to reject monophyly of Morunasaurus, suggesting that further study is needed to resolve its taxonomic status. Based on our results, we establish the converted clade names Hoplocercinae, Hoplocercus, Enyalioides, and Morunasaurus, as well as the new clade name Zimiamviasaurus.