Are the Ranidae ( Anura, Amphibia) known prior to the Oligocene?

Abstract

Early records of supposed Ranidae have been reported from the ante-Oligocene and even as early as the middle Jurassic. These should be either rejected from the Ranidae (most of them) or considered only as possible ranids. Some authors have indicated that ranids are known only since the Oligocene. True ante-Oligocene ranids occur in Europe (in the upper Eocene). They predate an important palaeobiological event: the 'Grande Coupure'. These Eocene ranids could be autochthonous, thus conveying the suggestion that Europe is the center or origin of the family, but this is unlikely. An alternative hypothesis is that these ranids are immigrants from Asia.-from Author