Meeting Abstract

32.6  Sunday, Jan. 5 09:15  Reanalysis of microRNAs reveals an archosaur rather than a lepidosaur affinity for turtles FIELD, D.J.*; KING, B.L.; GAUTHIER, J.A.; PETERSON, K.J.; Yale University; Mount Desert Island Biological Laboratory; Yale University; Dartmouth College

The phylogenetic interrelationships of the major amniote clades have received considerable attention in the last decade. Specifically, the topological placement of turtles (Testudines) within Amniota has been source of contention, with most morphological cladistic analyses suggesting that turtles are the sister taxon to the rest of Diapsida, and most molecular analyses advocating a position of turtles sister to, or within, Archosauria. Previously, a phylogenetic study investigating micro-RNAs (miRNAs) indicated that, contrary to most morphological and molecular datasets, turtles actually represent the sister taxon to Lepidosauria. Here, we reanalyze these data, employing stricter limits on the criteria for miRNA annotation, as well as an expanded taxonomic sample of expressed miRNAs and genomic sequences. We recover no support for the previously espoused turtle-lepidosaur sister-relationship, and rather recover strong support for turtles sharing a more recent common ancestor with archosaurs than with any other amniote clade. These results are in accordance with most recent molecular studies, providing strong, consilient evidence from independent datasets for the phylogenetic position of turtles.