The rodent fauna from Prat de Cest (Aude, France) and its biochronological implications for the Early Miocene

The new Prat de Cest locality (Narbonne-Sigean Basin, Aude, France) provides a rodent fauna composed of Pseudocricetodon thaleri, Simplomys aff. aljaphi, Vasseuromys cf. bergasensis, Plesiosminthus myarion and Rhodanomys occitanensis nov. sp. Eomyidae account for more than 78% of the material collected and reflect a humid and forested environment. The presence of Plesiosminthus myarion and Simplomys aff. aljaphi, the evolutionary stage of Pseudocricetodon thaleri, close to the population of Coderet (MP30) but displaying some derived characters shared by Early Miocene populations, and the intermediate morphology and size of R. occitanensis nov. sp. between Rhodanomys transiens and Rhodanomys schlosseri support a basal MN1 age for Prat de Cest. The glirid Vasseuromys cf. bergasensis is the first occurrence of this genus outside Spain and could also be the first occurrence of Vasseuromys bergasensis in the Early Miocene. The unique faunal association found in Prat de Cest paves the way for a possible subdivision of the MN1 biozone.