Developmental biology of the common marmoset: proposal for a "postnatal staging".

The published knowledge on neurobiological, psychological, and ethological aspects of development in Callithrix jacchus is still limited. We have collected published and unpublished data from several Callithrix colonies and pooled information on criteria for developmental progress and maturation using a questionnaire sent to numerous experts in the field. The data suggest that developmental stages can be defined not only for the embryonic and fetal but also for the postnatal period. Based on multifactorial definitions, using criteria selected from maturational changes in the motor and visual systems and behavioral features, we propose to subdivide postnatal development of the common marmoset into seven periods ("stages").