Unilateral ovarian absence in a Black-headed Squirrel Monkey (Saimiri vanzolinii Ayres, 1985), a threatened neotropical primate species.

Ovarian agenesis is an unusual anomaly with traumatic or congenital origin. In the present case report, we describe our findings in a senile S. vanzolinii female. As this neotropical primate species is listed as vulnerable, with limited geographic distribution in the Brazilian Amazonia, ovarian agenesis may be an important finding to be reported.