Gerobatrachus

Gerobatrachus, also referred to as a frogamander, is an extinct genus of amphibamid temnospondyl that lived in the Permian period, approximately 290 million years ago, in the area that is now Baylor County, Texas. Gerobatrachus has been considered to be one of the closest relatives to either Batrachia, the clade that includes frogs and salamanders, or to Lissamphibia, the clade that includes all modern amphibians (frogs, salamanders, and caecilians). Molecular clock estimates put the divergence of frogs and salamanders in the Late Carboniferous at sometime between 308 and 357 million years ago, but Gerobatrachus suggests that the two groups diverged several tens of millions of years later, between the appearance of Gerobatrachus in the Early Permian and the appearance of Triadobatrachus, the oldest definitive batrachian, in the Triassic.

A 2012 study of the stem-caecilian Eocaecilia found Gerobatrachus to group within Lissamphibia, the clade that includes all modern amphibians.