Pissinatti's saki

Pissinatti's saki, also called Pissinatti's bald-faced saki (Pithecia pissinattii), is a disputed species of saki monkey endemic to Brazil, where it lives south of the Solimões River between the Madeira and Purus rivers. A 2014 study split it from the Rio Tapajós saki on its distinctive pelage, but a 2019 study found that pelage within the range of variation of that species, and the American Society of Mammalogists tentatively treats it as a synonym, while the IUCN Red List and ITIS keep it. It is named for Alcides Pissinatti, a Brazilian veterinarian and co-founder of the Centro de Primatologia do Rio de Janeiro who pioneered captive breeding of endangered Brazilian primates. Both sexes have pink to dark red faces and black, grizzled fur, and males have an orange ruff. Logging and poaching are thought to threaten it and to be reducing its numbers, but it is poorly known and the IUCN lists it as Data Deficient.