#gelada

Someone who identified themself only as Pendrew asked for a "ruminant-like Old World Monkey":

After much of East Africa rifted off into a separate continent, shifting climate turned the alpine grasslands of what was once the Ethiopian Highlands into into warmer subtropical forests – and the highly terrestrial grass-eating geladas that inhabited the region adapted to new sources of food.

Yedenigelada pendrewsii is a large quadrupedal herbivorous monkey, about 1.5m tall at the shoulder (~5'). It has a specialized pseudoruminant digestive system with a three-chambered stomach, similar to that of camelids, and it occupies an ecological niche convergent with the ancient chalicotheres, selectively browsing on trees and shrubs while sitting upright and using its long clawed forelimbs to pull branches within reach. 

Unlike its highly social ancestors this species is mostly solitary, although during the breeding season groups of males come together in leks to compete for female attention. Displays consist of inflating large colorful throat pouches to make loud resonating calls, and flipping upper lips to bare teeth and gums.

Colored sketch of Seti, an anthro gelada baboon!

The Palubolígolian Gugwe (Gugwepithecus Mauli) is one of, if not the largest baboon of Palubolígo. This highly social monkey lives in groups of about a hundred in the Upper and Lower Simán mountain platoes. The Kongs, or Heavy Male Morph are mostly carnivorous and stays as the protector in the center of the troop, while the Sleek Male Morph is usually at the outside of the troop, they are pursuit predators and scout for danger. The females are the smarter sex, unlike the males, they are mostly herbivorous. During the night they sleep with the young in caves, while the males stand guard. Some groups even have females that use fire and simple tools.