Earliest New World monkey

The earliest known representative of the New World taxonomic monkey group Platyrrhini is Perupithecus ucayaliensis. It existed approximately 36 million years ago during the Eocene epoch in what is now Peru, and its fossil remains were discovered in 2010 by a palaeontological team led by Dr Kenneth Campbell of the Natural History Museum of Los Angeles County, USA. Approximately the size of a squirrel but with a longer tail, it probably weighed less than 0.25 kg.

10 million years older than any previous money fossils found in South America, although the first remains of Perupithecus were uncovered in 2010 it took another two years to confirm that they were indeed from a monkey, and the species' formal scientific description was not published until 2015.