Scientists have discovered two new species of monkeys in Brazil’s central Amazon, according to the Associated Press. Both types of monkeys are about the size of cats.

Above: Callicebus stephennashi. Below: Callicebus bernhardi.

“This once again demonstrates how little we know about biodiversity,” said Russell Mittermeier, president of Conservation International. “These are the 37th and 38th new primate species described since 1990.”

Mittermeier was also reportedly heard to comment that “monkeys are cool.” (Okay, maybe he didn’t say that. But they are!)

This monkey, meanwhile, does not belong to a newly discovered species: