[Morphologic and genetic differentiation of night monkey (Aotus infulatus, Primates, Platyrrhinians, Cebidae) populations from the right and left banks of Rio Tocantins (Brazil)].

The cranial morphology of 28 specimens of night monkeys (genus Aotus) was examined using three-dimensional geometrical morphometrics. New results of the morphological differences between two populations of Aotus infulatus from both banks of the Rio Tocantins are proposed. These morphological results totally agree with the genetic distinction of these populations proposed by Schneider -- and Sampaio --, and probably point out recent rapid evolutive changes for this species. Our morphometric results can be used for taxonomic, but also for medical research, as the susceptibility to malaria of night monkeys is variable between species.