Redescription and relationships of Saltenia ibanezi, a Late Cretaceous pipid frog from northwesthern Argentina

Abstract

The generic allocation of the late Cretaceous frog remains from Alemania, province of Salta, northwestern Argentina, has been a matter of dispute. They were considered either as representing a new probably aglossan genus and species, Saltenia ibanezi Reig, 1959, or referred to the African Palaeogene pipoid genus Eoxenopoides as E. saltensis Parodi Bustos et al., 1960. Examination of the original material on which those studies were based as well as recently collected specimens demonstrates that this anuran is clearly referable to the Pipidae, and its assigment to a separate genus is justified. Saltenia is thus the earliest known pipid frog from South America even though it occurs outside the present geographic range of pipids in this continent. It is suggested that the origin of Saltenia preceded that of Eoxenopoides and Xenopus. The latter genus is strictly African at present but the paleontologic data show that it was a component of the African and South American paleobatracofauna. Geologic and paleontologic evidence points to an early radiation of pipids over the South American-African block in the early Cretaceous, however it has not been documented yet in the fossil record.