Most likely it's a female. Sexually mature females can be twice as large as males reaching 100 mm (about 4 inches). Not sure of the species, but it looks very much like Lepidobatrachus laevis.

Sexually mature males possess a dark blue-black throat (Budgett 1899; Cei 1980)

Budgett, J. S. (1899). ''Notes on the batrachians of the Paraguayan chaco, with observations upon their breeding habits and development, especially with regard to Phyllomedusa hypochondrialis, Cope. Also a description of a new genus.'' The Quarterly Journal of Microscopical Science, 42(167), 305-333.

Cei, J. M. (1980). ''Amphibians of Argentina.'' Monitore Zoologica Italiano, New Series Monografia, Firenze, 2, 1-609.