The Paleocene locality of Punta Peligro (Hansen Member of the Salamanca Formation) in Argentina has yielded not only ‘condylarths’ but also an extraordinary assemblage of therian mammals derived from Laurasian immigrants and non-therian mammals, relicts of the Mesozoic Gondwanan radiation. The materials, a left jaw fragment with the talonid of the second molar and the third molar, and an isolated upper molar, allow the revalidation of Raulvaccia peligrensis considered previously as a junior synonym of Escribania chubutensis. In addition to other characters, Raulvaccia strongly differs from E. chubutensis in its lesser size, the development of the m3 talonid, the presence of a hypocristid, and a postcristid. Originally Raulvaccia and Escribania were considered as Mioclaenidae, Kollpaniinae, together with other ungulates from the Santa Lucía Formation, from the early Paleocene locality of Tiupampa in Bolivia. In contrast to the Tiupampan ‘condylarths,’ Raulvaccia shares derived characters with E. chubutensis, particularly in the upper molars, such as a strong parastyle and the presence of hypocone located close to, but well differentiated from the protocone. These characters support a previous hypothesis which argues for the removal of the Peligran ‘condylarths’ from the more primitive Kollpaniinae, and sustains its relationship to the exclusively South American Didolodontidae. The revalidation of Raulvaccia peligrensis shows that the diversity of placental mammals during the earliest known Paleocene in Patagonia was greater than previously thought, and supports for the early differentiation of the Didolodontidae.