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 ...

Quiet on the tee? The howler monkeys weren’t having it. Hidden in the canopy above me, the loudest mammals on the planet were holding forth in full-throated violation of golf etiquette: primates with ...

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 ...