The bones and teeth of the new species, now described as a "hominin", were found in the Callao Cave on Luzon.
The size of these remains suggests that the humans to whom they once belonged were also short of stature, not unlike those identified from H. floresiensis. Aside from Callao Cave, human fossils have recently been found in another site in Bulacan province just north of the capital, Manila, Mijares said without elaborating.
Callao Cave on Luzon Island of the Philippines where the fossils of Homo Iuzonesis were discovered.
Fossil bones and teeth found in the Philippines have revealed a long-lost cousin of modern people, which evidently lived around the time our own species was spreading from Africa to occupy the rest of the world.
The fossils from the seven-chamber cave, situated in the foothills of Luzon's northern Sierra Madre mountains, boasted a combination of anatomical features setting it apart from other human species.
Scientists described the new species this week in the journal Nature. Researchers weren't sure, however, and so they kept digging.
But some human relative was on Luzon more than 700,000 years ago, as indicated by the presence of stone tools and a butchered rhino dating to that time, he said.
Discovering a new species of ancient human is a career-maker in anthropology - or career-breaker, if you're wrong. They look more like what one what might find in Africa 1.5 to 2.5 million years ago, and which might have been carried out of that continent by the mystery species, he said.
Archaeologists, who discovered fossil bones and teeth of a previously unknown human species that thrived more than 50,000 years ago in the northern Philippines, have called for better protection of the popular limestone cave complex where the remains were unearthed.
The discovery of Homo luzonensis presents new questions about which hominins left Africa first and how hominin species ended up on island isolated by water.
Homo luzonensis had extraordinarily small adult molars - "they're close to half the size of adult modern human molars", Tocheri said. As far as experts were concerned, species like the Homo erectus ventured into Indonesia.
The finger bone also resembles that of Australopithecus, as well as early Homo species.
Mr Détroit said: "Arrival by accident ... is favoured by many scholars, but this is mainly because of arguments like "Homo erectus were not clever enough to cross the sea on purpose".
"In our disciplines, you can never expect to find a new species - this is a very rare event", said study lead author Florent Détroit, a paleoanthropologist at France's National Museum of Natural History in Paris. The researchers dubbed the new species Homo luzonensis after the island on which it was found. There is no indication the two species interacted or were closely related.
To go further east would be impossible, they say, since ocean currents would make it impassable for them.
The discovery of Homo floresiensis and Homo luzonensis "really exposes how little we know about human evolution in Asia", Tocheri said.
These discoveries, Potts says, "are going to play havoc with any easy classification" of our ancestors and with the notion that there was a fairly orderly progression from primitive to more "modern" traits.
With more evidence to examine, from at least three individuals, they were able to build the case that the remains came from a previously unknown type of human.