Solimoea acrensis

Solimoea acrensis is an extinct monkey from the Late Miocene Solimões Formation of Acre in western Brazil, and the only known species of the genus Solimoea. It was described by Richard Kay and Mario Alberto Cozzuol from a lower first molar and a maxillary fragment with two premolars, recovered in a joint expedition of the Universidade Federal do Acre and the University of Rondônia. Body mass has been estimated at roughly 5.4 to 8 kilograms, similar to modern woolly and spider monkeys. Its shearing crests point to a diet of soft fruit, close to that of Geoffroy's spider monkey. The describers placed it as the earliest ateline, although a 2015 study suggests it may instead belong with the howler monkey line, the Alouattinae. It shared its environment with a species of the stem howler Stirtonia and with the capuchin relative Acrecebus.