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.  

Methods
Polymerase Chain Reaction (PCR) amplification was performed in a final volume of 25 μl reactions using 1X PCR Buffer (–Mg), 3 mM MgCl2, 0.2 mM dNTP mix, 0.2 μM of each primer, 0.1 U/μl of Platinum® Taq DNA Polymerase (Invitrogen, Carlsbad, CA) and 1 μl of extracted DNA. PCR primers and protocols are presented in Table 1. Double stranded sequencing of the PCR products was performed in both directions by Macrogen Inc. (Seoul, Korea), except for those of H. spinosus, which were performed at the Laboratório Temático de Biologia Molecular from the Instituto Nacional de Pesquisas da Amazônia (LTBM/ INPA). We also retrieved from GenBank all available sequences of the genes mentioned above for all species of hoplocercine lizards and the outgroups. All terminals in gene trees correspond to single specimens except for Enyalioides microlepis, E. palpebralis and E. touzeti, which are composed of sequences of two specimens from localities 204.32 km, 56.16 km, and 35.88 km (great circle distances calculated in www.gpsvisualizer.com) apart, respectively. Similarly, outgroup species are represented by sequences of more than one specimen.