Coati are related to many types of extinct animal, but they are most closely related to animals like the Cyonausa, whose name in Greek literally translates to "dog-coati."

In fact, it's thought that members of the Procyonidae family, which includes coati, raccoons, and cyonusa, originated from a common ancestor of wolves and dogs. This ancestor became more omnivorous, which means eating more plants and less meat, and adapted to its environment, resulting in the coati we see today.

They think coatis separated from raccoons 5 or 10 million years ago. Not much is known about coati evolution.*

Coatis are in the genetic Order of Carnivores, which are either dogs or cats. Coatis are in the dog category.

*Fossil coatis are rare, and the fossil record and evolutionary history of this species is poorly understood. A few incomplete fossils exist from the United States and from South America (Brazil and Bolivia), and none from Central America. Most of the range of the species is or was tropical forest, which is not conducive to fossil formation. What little can be deduced from existing fossils suggests that the species may have diverged from a raccoon lineage approximately 4.5-9.5 million years ago. Laboratory studies that compare the DNA and proteins of coatis and other small carnivores confirm that the species is genetically most closely related to raccoons and ringtails. People often recognize this relationship because of the similar mask-like facial markings and ringed tails of these species.

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