Why is a baboon considered to be a monkey?

Monkeys are haplorhine (dry nosed) primates of which there are over 250 species. In this group are New World Monkeys and catarrhines. Catarrhines can be further divided into Old World Monkeys and Apes. Most monkey species have tails, but not all. read more

I'm going to assume that you are asking why baboons are considered monkeys rather than apes. In standard English usage a big part of what distinguishes apes from their monkey cousins is having no tail. I have even heard people say that “ape” just means “a monkey without a tail.” Biologists usually focus on common descent. read more

This particular Monkey is often argued to be an Ape instead. However, science has placed them into the area of being a Monkey based on a variety of contributing factors. There are 5 species of the Baboon and they are all part of the Old World Monkeys. read more