Spider monkey wildlife, looking at the camera.

Spider monkeys, maquisapas, marimondas, marimonos, koatás or atelos, is the common name for any of the primates of the genus Ateles ("without thumb") belonging to the family Atelidae. The name Ateles refers to the absence of an opposable thumb in the species of the genus; it only has a vvestigial appendage. They measure between 60 and 90 cm in length. They are gregarious in groups of 6 to 30 individuals and very arboreal. Their prehensile tail helps them to move nimbly between trees. They feed on fruits and insects. They live in tropical forests, from Mexico to Brazil.

Depending on the species, their body length ranges from 65 to 90 cm, and the prehensile tail from 60 to 92 cm. They are more slender in appearance than other monkeys of the Atelidae family and weigh between 7 and 10 kg. They have four toes and no thumb. The body is elongated and the limbs are long; the color of the different species varies from light brown to black.