A dataset of new occurrence records of primates from the arc of deforestation, Brazil.

​​​​​​​The so-called arc of deforestation is a major agricultural and industrial frontier in southern Amazonia and northern Cerrado of Brazil. As arboreal mammals, the primates in this region are therefore threatened by forest loss and fragmentation. At the same time, knowledge about the taxonomic diversity and distribution ranges of these taxa is incomplete, which might hamper efficient conservation measurements. New species have been recently discovered in this region, and their ranges remain imprecise because only a few occurrence records are available for each species. Here we present 192 new records of 22 species and subspecies of Alouatta, Aotus, Ateles, Cebus, Chiropotes, Lagothrix, Leontocebus, Pithecia, Plecturocebus, Saimiri, and Sapajus, collected in 56 different localities during 10 field expeditions across the arc of deforestation between 2015 and 2018. Based on these new records, we extend the ranges of Alouatta puruensis, Ateles chamek, and Saimiri collinsi; identify potential hybridization zones between A. puruensis and A. discolor, and between At. chamek and At. marginatus; redefine the range of Plecturocebus moloch; and clarify the ranges of P. baptista and P. hoffmannsi. Moreover, these results and the dataset are valuable for further research on, for example, species distribution and habitat use modeling, for assessing species extinction risks, and for supporting efforts for the conservation of species increasingly threatened on a global deforestation frontier.