Geoffroy's marmoset is a small monkey with dark ear tufts and a white face. It lives in Brazil's lowland rainforests, where group members help care for young.
Males and females look similar. It has a blackish-brown coat, long black ear tufts, a white forehead, cheeks and throat, and a black tail with faint rings.
It lives in social groups where fathers and other members help care for young. Older offspring may remain in the group and help care for younger siblings.
An extinction-risk assessment has not been added yet.