Monday, December 19, 2016

[Herpetology • 2017] Extended Molecular Phylogenetics and Revised Systematics of Malagasy Scincine Lizards


Fig. 1. Phylogeny of Malagasy scincine lizards, based on a 50% majority rule consensus tree inferred through Bayesian analysis of 12 concatenated loci (3 mtDNA, 9 nDNA) comprising 8060 bp (outgroups not shown). Node values represent posterior probability from BI and bootstrap support from ML and MP analyses, respectively (see Fig. SM2). Bootstrap values under 70 are not displayed and denoted with a dash. Dashed branches indicate the tentative placement of taxa with multiple missing data (as inferred with a second Bayesian analysis) and with posterior probabilities in parentheses. Clades characterized by quadrupedal taxa are highlighted in color, while the clades consisting of limb-reduced fossorial taxa are highlighted in grey. For Grandidierina fierinensisParacontias mahamavo and P. ampijoroensis, two individuals each were included in the analyses (see Table SM1) that showed very low intraspecific genetic divergence, and were collapsed in the tree to display all terminal taxa at the species level. The three candidate species of Amphiglossus are named according to provisional names used in Glaw and Vences (2007).

 Highlights
• A new phylogenetic hypothesis for Malagasy scincines based on an extended multilocus dataset.
• Phenotypic comparisons corroborate divergent molecular patterns of evolution.
• Three separate clades of Amphiglossus, characterized by different degrees of body elongation.
• Amphiglossus redefined into three different genera based on combined molecular and morphological findings.

Abstract
Among the endemic biota of Madagascar, skinks are a diverse radiation of lizards that exhibit a striking ecomorphological variation, and could provide an interesting system to study body-form evolution in squamate reptiles. We provide a new phylogenetic hypothesis for Malagasy skinks of the subfamily Scincinae based on an extended molecular dataset comprising 8060 bp from three mitochondrial and nine nuclear loci. Our analysis also maximizes taxon sampling of the genus Amphiglossus by including 16 out of 25 nominal species. Additionally, we examined whether the molecular phylogenetic patterns coincide with morphological differentiation in the species currently assigned to this genus. Various methods of inference recover a mostly strongly supported phylogeny with three main clades of Amphiglossus. However, relationships among these three clades and the limb-reduced genera GrandidierinaVoeltzkowia and Pygomeles remain uncertain, mainly based on maximum likelihood and maximum parsimony estimates. Supported by a variety of morphological differences (predominantly related to the degree of body elongation), but considering the remaining phylogenetic uncertainty, we propose a redefinition of Amphiglossus into three different genera (Amphiglossus sensu strictoFlexiseps new genus, and Brachyseps new genus) to remove the non-monophyly of Amphiglossus sensu lato and to facilitate future studies on this fascinating group of lizards.

Keywords: Madagascar; Skinks; Phylogeny; Morphology; Taxonomy; Scincidae




Jesse Erens, Aurélien Miralles, Frank Glaw, Lars Chatrou and Miguel Vences. 2017. Extended Molecular Phylogenetics and Revised Systematics of Malagasy Scincine Lizards. Molecular Phylogenetics and Evolution. In Press. DOI: 10.1016/j.ympev.2016.12.008

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