Which specific physical feature serves as a key identifier for the Pygmy Marmoset among other marmosets?

Answer

Pointed ear tufts, sometimes called ear tassels

A distinctive feature of this species, contributing to its unique profile, is the frequent display of pointed ear tufts.

Which specific physical feature serves as a key identifier for the Pygmy Marmoset among other marmosets?
animalcharacteristicPrimateFinger Monkey