East Sumatran banded langur
The East Sumatran banded langur, also known as the East Sumatran banded surili, is a species of monkey in the family Cercopithecidae. It was formerly considered a subspecies of the Raffles' banded langur Presbytis femoralis, but genetic analysis revealed it to be a separate species. Its range is restricted to the Riau Province of east-central Sumatra. Due to its declining population and restricted range in small, isolated forests subject to high rates of deforestation, the IUCN declared it to be a critically endangered species in 2020.