A new European Late Jurassic pleurosternid (Testudines, Paracryptodira) and a new hypothesis of paracryptodiran phylogeny

Abstract

Paracryptodira was an abundant and diverse group of freshwater turtles, recognized both in North America and Europe. Its known record spans the Middle Jurassic to the Eocene. The internal phylogenetic relationships of one of its clades, Baenidae, are relatively well known. However, information on the relationships amongst the non-baenid members is very limited and, so far, poorly justified. A new study on the phylogenetic relationships amongst Paracryptodira is undertaken here through the revision of previously described taxa, the incorporation of information on taxa recently discovered or revised, and the study of new material. In addition, a new taxon from the Late Jurassic of Europe is described: Riodevemys inumbragigas gen. et sp. nov. It is identified as a member of Pleurosternidae, constituting the first generic and specific attribution of a pleurosternid in the Spanish fossil record. Pleurosternidae is obtained here as a robust node whose composition differs from previous proposals. The relationships amongst representatives are analysed. In addition, we define a new clade, Compsemydidae, identified as the sister group of Baenoidea (Baenidae + Pleurosternidae). The new phylogenetic proposal, and its analysis in view of stratigraphical distributions, shows that Baenidae was a clade of turtles only known in the Cretaceous and Palaeogene of the North American record but that Pleurosternidae and Compsemydidae were distributed both in North America and Europe. The temporal distribution of Pleurosternidae is restricted here, refuting some putatively older and younger occurrences. This new hypothesis restricts its known distribution to the Late Jurassic of North America and the Late Jurassic and the first part of the Early Cretaceous of Europe. The new clade Compsemydidae is recognized in the Late Cretaceous and Palaeocene of North America and in younger levels of the European Palaeocene.

http://zoobank.org/urn:lsid:zoobank.org:pub:1BA05241-4DAE-490F-B454-4CF32BCA4B42

Keywords:

• Paracryptodira
• Pleurosternidae
• phylogeny
• northern hemisphere

Acknowledgements

The authors thank Luis Alcalá (FCPTD) and Eduardo Espílez (FCPTD) for access to material; Juliana Sterli, an anonymous reviewer and Xabier Murelaga for comments and suggestions; and Christine Laurin for revising the English text. APG thanks Francisco Gascó for his hospitality while the holotype of the new pleurosternid was prepared and studied. The Willi Hennig Society sponsors TNT cladistics software. This study is part of the palaeontological research projects of the Departamento de Educación, Universidad, Cultura y Deporte, Gobierno de Aragón and has been supported by its Dirección General de Patrimonio Cultural (Exp. 252/02/2003, 142/2003, 142/03/2004, 197/2005, 241/2006, 201/2007, 227/2008, 228/2008, 079/2009, and 104/2010), DINOSARAGÓN CGL2009-07792 R&D project (Ministerio de Ciencia e Innovación and FEDER Funds), FOCONTUR (Grupo de Investigación Consolidado E-62, Departamento de Industria e Innovación, Gobierno de Aragón and Fondo Social Europeo), Instituto Aragonés de Fomento, and Fundación Conjunto Paleontológico de Teruel-Dinópolis. It is also part of the GIU12/35 research group (University of the Basque Country).

Supplemental Material

Supplemental material for this article can be accessed doi.org/10.1080/14772019.2014.911212