Aotidae – Night monkeys

The only nocturnal primates of the New World

New world monkeys are among the most species-rich lineages. They presumably arrived in Southern America through transoceanic dispersal during the Eocene.

The Aotidae family is of night monkeys classified in the genus Aotus grouped in a red-necked group and a gray-necked group containing several species. Previously due to a lack of chromosomal data, Genus Aotus was considered a subfamily within the Cebidae. The extinct species (fossil) can be traced to the early Miocene era.

They are relatively small-sized, with round heads, flat-rounded faces, large eyes, hidden ears, and long bushy (non-prehensile) tails that help them balance. Many Aotus species have been used for vaccine research, virological studies, and vision physiology.

Did you know…?

The name Aotis is derived from the Latin a-meaning without, and otis- meaning ear, i.e., without an ear. Their ears are actually hidden in thick fur.
They sleep together in trees during the day and remain active at night; the only haplorrhines are primarily active at night.
The eyes’ morphology confirms their nocturnality derived from a diurnal antecedent.
Typically live at moderate elevation and have thicker fur coats than other New world monkeys.
They use a great deal of vocal communication.
Their eyes are large to capture more light and enhance their vision, but they lack color vision.