Data from: Cranial and post-cranial remains and phylogenetic relationships of the Gondwanan meiolaniform turtle Peligrochelys walshae from the Paleocene of Chubut, Argentina

Peligrochelys walshae is a meiolaniform turtle originally described based on one specimen represented by cranial remains found in the classic locality of Punta Peligro (Chubut, Argentina) in outcrops of the Salamanca Formation (Danian). Recent field works in the vicinity of Punta Peligro resulted in the discovery of almost 30 new specimens, represented by cranial and postcranial remains that can be assigned to P. walshae. In this contribution we provide a detailed anatomical description of the new specimens, provide an emended diagnosis for the species, and explore its phylogenetic relationships based on all anatomical data available for the species. The new specimens bring valuable information about the anatomy of the skull and postcranium of P. walshae as well as for meiolaniforms in general. The 3D preservation of the skull bones allows us to provide a 3D reconstruction using novel techniques. The updated phylogenetic analysis confirms that P. walshae is part of the clade Meiolaniformes, which spans from the Early Cretaceous until the Holocene and contains the giant, horned turtles (Meiolaniidae). This phylogenetic analysis reinforces the previously hypothesis that the clade Meiolaniformes is dominated by Gondwanan taxa, but also includes some Laurasian representatives. Alternate phylogenetic positions of taxa included in Meiolaniformes in this analysis were tested using the Templeton test. The lineage leading to Peligrochelys walshae is the only meiolaniform non-meiolaniid lineage to have survived the K-Pg mass extinction; its study provides valuable information to evaluate the effects of the K-Pg extinction in turtles.Supplementary Data 1. List of specimens used in this work; list of 3D scanned specimens; construction of the phylogenetic matrix; list of synapomorphies common to all most parsimonious trees.SD 1.docxSupplementary Data 2. 3D reconstruction of Peligrochelys walshae skull.SD 2.pdfSupplementary Data 3. Morphological matrix in nexus format.SD 3.nexSupplementary Data 4. Morphological matrix in tnt format.SD 4.tntSupplementary Data 5. Constraints used in the constrained analysis based on Joyce et al. (2016) and Pérez-García and Codrea (2017).SD 5.tifSupplementary Data 6. Script of Templeton test.SD 6.runSupplementary Data 7. Most parsimonious trees in ctf format (for TNT).SD 7.ctfSupplementary Data 8. Strict consensus tree of 10.000 most parsimonious trees of 966 steps found in the unconstrained analysis.SD 8.tifSupplementary Data 9. Most parsimonious trees in ctf format (for TNT) of the constrained analysis.SD 9.ctfSupplementary Data 10. One most parsimonious tree selected at random and one constrained tree selected at random in ctf (for TNT) used to run the Templeton test.SD 10.ctfSupplementary Data 11. Result of the Templeton test.SD 11.doc