The South American Marmoset is a type of small monkey found in the tropical forests of South America. It is closely related to the Tamarin, which is a seven-letter word for a type of small monkey found in Central and South America. The Titi is another four-letter word for a type of South American monkey that is closely related to the Marmoset. Both the Tamarin and the Titi are known for their long, bushy tails and their ability to live in large groups.