Scientists digging in the Liang Bua cave on the Indonesian island of Flores years ago found a tiny humanlike skull, then a pelvis, jaw and other bones, all between 60,000 and 100,000 years old.

The fossils, the scientists concluded, belonged to individuals who stood just three feet tall — an unknown species, related to modern humans, that they called Homo floresiensis or, more casually, the hobbits.

On Wednesday, researchers reported that they had discovered still older remains on the island, including teeth, a piece of a jaw and 149 stone tools dating back 700,000 years. The finding suggests that the ancestors of the hobbits arrived on Flores about a million years ago, the scientists said, and evolved into their own distinct branch of the hominin tree.

But without other parts of a skeleton, such as the skull, hands or feet, they can’t be sure whether the newly discovered fossils also belong to Homo floresiensis or instead to some other ancient relative of humans (known generally as hominins).