title: Phylogenetic analyses of complete mitochondrial genome sequences suggest a basal divergence of the enigmatic rodent Anomalurus.
abstract: BACKGROUND
  Phylogenetic relationships between Lagomorpha, Rodentia and Primates and their allies (Euarchontoglires) have long been debated. While it is now generally agreed that Rodentia constitutes a monophyletic sister-group of Lagomorpha and that this clade (Glires) is sister to Primates and Dermoptera, higher-level relationships within Rodentia remain contentious.
  
  
  RESULTS
  We have sequenced and performed extensive evolutionary analyses on the mitochondrial genome of the scaly-tailed flying squirrel Anomalurus sp., an enigmatic rodent whose phylogenetic affinities have been obscure and extensively debated. Our phylogenetic analyses of the coding regions of available complete mitochondrial genome sequences from Euarchontoglires suggest that Anomalurus is a sister taxon to the Hystricognathi, and that this clade represents the most basal divergence among sampled Rodentia. Bayesian dating methods incorporating a relaxed molecular clock provide divergence-time estimates which are consistently in agreement with the fossil record and which indicate a rapid radiation within Glires around 60 million years ago.
  
  
  CONCLUSIONS
  Taken together, the data presented provide a working hypothesis as to the phylogenetic placement of Anomalurus, underline the utility of mitochondrial sequences in the resolution of even relatively deep divergences and go some way to explaining the difficulty of conclusively resolving higher-level relationships within Glires with available data and methodologies.
authors.affiliation: Dipartimento di Scienze Biomolecolari e Biotecnologie, Università di Milano, Via Celoria 26, 20133 Milano, Italy. david.horner@unimi.it <david.horner@unimi.it>
authors.forename: David S
authors.initials: DS
authors.lastname: Horner
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Lefkimmiatis
authors.forename: Aurelio
authors.initials: A
authors.lastname: Reyes
authors.forename: Carmela
authors.initials: C
authors.lastname: Gissi
authors.forename: Cecilia
authors.initials: C
authors.lastname: Saccone
authors.forename: Graziano
authors.initials: G
authors.lastname: Pesole
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D004272:DNA, Mitochondrial / Q000235:genetics*; D019143:Evolution, Molecular; D016678:Genome; D010802:Phylogeny; D012377:Rodentia / Q000145:classification / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial