Larachelus morla, gen. et sp. nov., a new member of the little-known European Early Cretaceous record of stem cryptodiran turtles

ABSTRACT

A relatively diverse record of European Early Cretaceous pan-cryptodiran turtles has been revealed from the analysis of new specimens and from a review of previously defined taxa. However, knowledge about many of these taxa remains relatively limited. We erect the new taxon, Larachelus morla, gen. et sp. nov., on the basis of a shell from the late Hauterivian–early Barremian of the Iberian Range (Spain). The comparative study of this taxon with the continental European Cretaceous pan-cryptodiran representatives and cladistic analyses reveal L. morla to be a member of the little-known European Early Cretaceous stem Cryptodira. Stem cryptodirans have been recognized from the Early Cretaceous of several continents. The study of L. morla not only confirms the presence of this group in the Early Cretaceous of Europe, it also provides new insights into the European evolution of Pan-Cryptodira. This finding reveals greater diversity in European Early Cretaceous continental pan-cryptodires, highlighting its Hauterivian–Aptian record. This diversity is particularly relevant in the Iberian Range, where several clades of turtles whose coexistence has not been recognized in the Lower Cretaceous of any other region are identified: paracryptodiran members, stem cryptodiran turtles, and representatives of several lineages of the crown group Cryptodira. This very high diversity of continental taxa shows a wide range of morphological diversity that could be related to adaptation to different ecological niches.

ACKNOWLEDGMENTS

The authors thank F. Torcida Fernández-Baldor and staff of the MDS for their cooperation and assistance; S. Chapman (NHMUK) and staff of the CAMSM, DORCM, ICIPLR, IRSNB, IWCMS, MCCM, MPG, and OXFUM for access to material; S. Modesto, F. Ortega, N. Vitek, and an anonymous reviewer for comments and suggestions; and C. Laurin for revising the English text. This research received support from the SYNTHESYS Project http:/www.synthesys.info/, which is financed by European Community Research Infrastructure Action under the FP7 Integrating Activities Programme. A.P.G. is funded by the FPU subprogramme of the “Ministerio de Ciencia e Innovación” (ref. AP2007-00873). The Willi Hennig Society sponsors TNT cladistics software.

Handling editor: Sean Modesto