 Fossils of "Rhynchippus" have been found in various fossiliferous stratigraphic units in South America, all restricted to the Deseadan South American land mammal age.Several specimens come from the Sarmiento Formation in the Golfo San Jorge Basin in southern Patagonia, with other finds from the Petaca Formation of the Subandean Belt in Bolivia, the Salla Formation from the same country, and the Tremembé Formation of the Taubaté Basin in eastern Brazil.The Sarmiento and Salla Formations have provided a rich assemblage of many mammals and terror birds, as "Physornis".