Acta Palaeontologica Polonica

A new bernissartiid crocodyliform from the Lower Cretaceous Wessex Formation (Wealden Group, Barremian) of the Isle of Wight, southern England

Steven C. Sweetman, Ulysse Pedreira-Segade, and Steven Vidovic

Acta Palaeontologica Polonica in press
available online 11 Mar 2014 doi:http://dx.doi.org/10.4202/app.00038.2013

A substantially complete skull of a small crocodyliform recently found on the foreshore near Yaverland on the south-east coast of the Isle of Wight, southern England is described. The locality, mode of preservation and associated matrix indicate that it is derived from one of the plant debris beds of the Lower Cretaceous Wessex Formation (Barremian, Wealden Group). The dentition, unique among crocodyliforms, serves to confirm that the specimen is referable to the, until now, monotypic family Bernissartiidae Dollo, 1883. Apomorphies, including placement of the choana and disposition of cranial sutures demonstrate that the Isle of Wight skull cannot be referred to Bernissartia fagesii Dollo, 1883, known from contemporaneous strata. Furthermore, these characters indicate that the specimen should not be referred to a new species of Bernissartia. Uniquely among non-eusuchian neosuchian crocodyliforms, the choana appears to be bounded entirely by the pterygoids, although occupying an extreme anterior position within them. The specimen is therefore placed in a new genus and species, Koumpiodontosuchus aprosdokiti. The systematic position of Bernissartiidae, and characters used to diagnose Eusuchia are discussed.

Key words: Eusuchia, Neosuchia, Bernissartiidae, crocodyliform, Barremian, Wealden, Cretaceous, England.

Steven C. Sweetman [steven.sweetman@port.ac.uk] and Steven U. Vidovic [steven.vidovic@port.ac.uk], Palaeobiology Research Group, School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth, PO1 3QL, United Kingdom; Ulysse Pedreira-Segade [xxxulysse.pedreirasegade@ens-lyon.fr], Departement des Sciences de la Terre, Universite Claude Bernard Lyon 1 et Ecole Normale Superieure de Lyon, 2 rue Dubois, 69622 Villeurbanne cedex, France.