Tremacebus
Tremacebus is an extinct genus of New World monkeys from the Early Miocene. The type species is T. harringtoni.Description
Tremacebus was about in length, and would have resembled a modern night monkey, to which it may have been related. However, its eyes appear to have been smaller than the modern species, CT scans of the cranium suggest a relatively small olfactory bulb and poor sense of smell, compared with night monkeys. These features suggest that it may not have been nocturnal.
Only a few fossils have been found, including a skull from the Sarmiento Formation, Patagonia.
