Thirteen million years ago, a medium-sized monkey known for guarding its territory among the treetops with a fearsome "howl" started doing something new. This monkey, one of the oldest known ancestors ...

Monkeys live throughout Asia, Africa, Central America, and South America. They’re distinct from other types of primate, like great apes (gorillas, chimpanzees, orangutans, bonobos, gibbons) and ...

13.3-million–13.6 million-year-old fossils from an extinct relative of the howler monkey show signs of being the first leaf-eating primate in South and Central America. Fossils from jaws of Stirtonia ...