What infraorder defines tamarins as New World monkeys?

Answer

Platyrrhini

Tamarins fall squarely into the Platyrrhini group, which designates them as New World monkeys. This infraorder is characterized geographically by primates found in Central and South America, and anatomically often by nostrils that are broad and face sideways. This classification places them distinctly separate from Old World monkeys and apes, which belong to the catarrhine lineage, characterized by downward-facing nostrils.

What infraorder defines tamarins as New World monkeys?
Monkeytamarinape