title: Molecular systematics of primary reptilian lineages and the tuatara mitochondrial genome.
abstract: We provide phylogenetic analyses for primary Reptilia lineages including, for the first time, Sphenodon punctatus (tuatara) using data from whole mitochondrial genomes. Our analyses firmly support a sister relationship between Sphenodon and Squamata, which includes lizards and snakes. Using Sphenodon as an outgroup for select squamates, we found evidence indicating a sister relationship, among our study taxa, between Serpentes (represented by Dinodon) and Varanidae. Our analyses support monophyly of Archosauria, and a sister relationship between turtles and archosaurs. This latter relationship is congruent with a growing set of morphological and molecular analyses placing turtles within crown Diapsida and recognizing them as secondarily anapsid (lacking a skull fenestration). Inclusion of Sphenodon, as the only surviving member of Sphenodontia (with fossils from the mid-Triassic), helps to fill a sampling gap within previous analyses of reptilian phylogeny. We also report a unique configuration for the mitochondrial genome of Sphenodon, including two tRNA(Lys) copies and an absence of ND5, tRNA(His), and tRNA(Thr) genes.
mesh_terms: D000818:Animals; D019070:Cell Lineage; D004247:DNA / Q000737:chemistry / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics* / Q000378:metabolism; D016678:Genome; D008928:Mitochondria / Q000235:genetics*; D010802:Phylogeny; D012343:RNA, Transfer / Q000378:metabolism; D012104:Reptiles; D013045:Species Specificity; D014426:Turtles / Q000235:genetics; D014714:Vertebrates
chemical_list: D017931:DNA Primers; D004272:DNA, Mitochondrial; D004247:DNA; D012343:RNA, Transfer