Résumé
Pomata-Ayte is a classic fossiliferous locality located in the Bolivian Altiplano (Oruro Department). First reported by Hoffstetter in 1972, it comprises a series of continental deposits assigned to the Pliocene–Pleistocene Umala Formation. Previous data on the Cingulata (armored xenarthrans) from this locality are scarce and limited to brief mentions of indeterminate glyptodonts, armadillos and the pampatheriid Plaina sp. for the Pliocene levels. We report and describe the diversity of cingulates recovered from Pomata-Ayte, including two different assemblages mostly represented by osteoderms and dorsal carapace fragments. The older assemblage belongs to the Early Pliocene (>5.27 Ma), while the younger corresponds to the Pleistocene (no radioisotopic dating available). For the Early Pliocene, records include representatives of Chlamyphoridae (Chorobates villosissimus and Macrochorobates scalabrinii), Pampatheriidae (Plaina intermedia), and Glyptodontidae (Plohophorini indet). These represent the first records of C. villosissimus and M. scalabrinii in Bolivia, extending their known paleogeographic distribution northwards. The Plohophorini is represented by several dorsal carapace osteoderms, which may belong to either Cranithlastus or Stromaphorus, two closely-related genera with similar osteoderm morphologies. This assemblage shows great affinities with those recorded for Lower Pliocene deposits at higher latitudes, particularly Northwestern Argentina, which contrasts with the endemic pattern recorded for other mammalian clades, including Notoungulata and Folivora, over Pliocene times in the Bolivian Altiplano. For the Pleistocene, records include Chlamyphoridae (Chaetophractus vellerosus) and Glyptodontidae (Glyptodon sp. and Doedicurini indet.). Chaetophractus vellerosus still inhabits the Bolivian Altiplano, so this record traces its presence in the area back to the Pleistocene. Regarding the osteoderms of Doedicurini indet., they are smaller, less thick, and they have a different foramina configuration compared to other Pliocene and Pleistocene doedicurines, which may indicate the presence of a new morphotype in the area. However, more complete materials are needed to corroborate this hypothesis.