Which primate family includes marmosets and tamarins?

The primate family that includes marmosets and tamarins is Callitrichidae.

Callitrichidae is a family of small New World monkeys native to Central and South America. It includes marmosets, tamarins, and lion tamarins, grouped across genera such as Callithrix, Mico, Cebuella, Saguinus, and Leontopithecus. Their small size, claw-like nails, and frequent use of tree sap and gum are characteristic features of the group.

Callitrichids are especially notable for their social and reproductive biology. Groups commonly contain several adults and helpers, while cooperative care of infants is widespread. Many species regularly produce twins, and males and older offspring can carry and care for young. Marmosets also show unusual adaptations for extracting tree exudates, including specialized teeth.

The main taxonomic wrinkle is rank. Some modern classifications treat Callitrichidae as the subfamily Callitrichinae within the broader family Cebidae. Nevertheless, Callitrichidae is a standard family-level answer and is the only option that directly names the marmoset-and-tamarin group in this quiz.