In a cave in the Philippines, scientists have discovered a new branch of the human family tree.

At least 50,000 years ago, an extinct human species lived on what is now the island of Luzon, researchers reported on Wednesday. It’s possible that Homo luzonensis, as they’re calling the species, stood less than three feet tall.

The discovery adds growing complexity to the story of human evolution. It was not a simple march forward, as it once seemed. Instead, our lineage assumed an exuberant burst of strange forms along the way.

Our species, Homo sapiens, now inhabits a comparatively lonely world.

“The more fossils that people pull out of the ground, the more we realize that the variation that was present in the past far exceeds what we see in us today,” said Matthew Tocheri, a paleoanthropologist at Lakehead University in Canada, who was not involved in the new discovery.