Plestiodon

Brandley, Matthew C., Fls, Hidetoshi Ota, Hikida, Tsutomu, Oca, Adrián Nieto Montes De, Fería-Ortíz, Manuel, Guo, Xianguang & Wang, Yuezhao, 2012, The phylogenetic systematics of blue-tailed skinks (Plestiodon) and the family Scincidae, Zoological Journal of the Linnean Society 165 (1), pp. 163-189 : 169-171

PLACEMENT OF PLESTIODON

Support for the monophyly of Scincidae is strong, and there is equally strong support for the subfamily Acontinae (represented here by Typhlosaurus sp. ) as the sister taxon to all remaining skinks ( Fig. 2 ). The basal relationships among the non-acontines are generally weak. There is no significant support for the placement of Ophiomorus and Brachymeles , although RAG1 supports the placement of both genera in a clade containing all other ‘scincines’ ( Fig. S1 ). However, there is strong support for Lygosominae monophyly and a clade containing the remaining

0.05 substitutions/site

‘scincines’. We did not sample the monotypic Feylinae, but previous studies have strongly supported its placement in a clade with Melanoseps (included in this study) and Typhlacontias (not included in this study) ( Whiting et al., 2003; Brandley et al., 2005). The ‘scincine’ clade splits into a strongly supported clade of African, Malagasy, and Seychellois taxa and a weakly supported clade (PP = 0.63), containing primarily northern hemisphere species, including all genera of Eumeces s.l. ( Eumeces s.s., Eurylepis , Mesoscincus , and Plestiodon ), Scincopus , and Scincus . The placement of Mesoscincus is weakly supported (PP = 0.50), but the primarily Northern African and Central Asian genera of Eurylepis , Eumeces s.s., Scincus , and Scincopus form a well-supported clade. The precise placement of Plestiodon is not strongly supported (PP = 0.63), but there is a strong support for its inclusion in the larger ‘scincine’ clade, to the exclusion of the Africa + Madagascar + Seychelles clade.

Although numerous scincid relationships differ between the nine loci and concatenated analyses, only one of these differences is strongly supported ( Fig. S1 ); most loci and the concatenated data infer strong support for Scincella ( Sphenomorphus group) as the sister taxon to the remaining lygosomines, but the mtDNA infers strong support for the sister relationship between Scincella and Trachylepis ( Mabuya group). There are three cases where the concatenated data and analyses of eight of the nine loci cannot estimate the phylogenetic placement of a taxon with

0.05 substitutions / site strong support, yet this relationship is strongly supported in one locus. In the first case, RAG1 data support a basal split of the non-acontine skinks into lygosomines and all sampled ‘scincines’ ( Fig. S1 ). In addition, these data strongly support the inclusion of Mesoscincus in a clade including Eumeces s.s., Eurylepis , Scincus , and Scincopus . The SNCAIP data strongly support the inclusion of Brachymeles in a clade containing lygosomines, but given the poor support within this clade, we cannot distinguish whether Brachymeles represents the sister lineage to lygosomines or disrupts lygosomine phylogeny ( Fig. S1 ). We note that none of these relationships strongly conflicts with the concatenated data analysis ( Fig. 2 ).

Figures

Figure 1. The geographical distribution of Plestiodon, with an inset showing the Ryukyu Islands.

Figure 2. The inter-relationships of the major lineages of Scincidae, including the placement of Plestiodon, inferred by partitioned Bayesian analysis of the entire concatenated multilocus DNA data set. Nodes with open circles are supported with a posterior probability of 1.0. Nodes with a posterior probability <1.0 are indicated with numbers above or below the node. Branch lengths represent means of the posterior distribution. Taxa once considered part of the genus Eumeces s.l. are shaded in grey.