April 10 (UPI) -- Scientists announced the discovery of a new species of ancient human, Homo luzonensis, on Wednesday.
The remains of the new human species, found in a cave in the Philippines, was first described in 2010, but paleontologists estimated that the fossil represented a diminutive Homo sapien. Researchers weren't sure, however, and so they kept digging. The recovery of additional bones proved the fossil belonged to a unique species.
At the completion of excavations on the island of Luzon, scientists had unearthed several teeth, part of a thigh bone, and a few hand and foot bones. The fossils comprise the "the earliest direct evidence of a human presence in the Philippines," according to the latest study.
The fossilized bones, dated to between 67,000 and 50,000 years ago, feature a mix of anatomical characteristics, some that recall more primitive hominins and others similar to those of more modern human species.
Scientists described the new species this week in the journal Nature.
Before Neanderthals or Homo sapiens ever left Africa and spread across Europe and Eurasia, earlier hominins left Africa and made their way across Eurasia, beginning unique experiments in human evolution.
The discovery of the "Hobbit" fossil, representing the hominin species Homo floresiensis, on the Indonesian island of Flores in 2004, proved some of these experiments made their way to the isolated laboratories of Southeast Asian islands.
The latest finding -- the discovery of a second hominin species in the region -- underscores the major role Southeast Asian islands played in the evolutionary history of hominins.
With each new discovery, the story of human evolution becomes increasingly complicated. Other excavations on Luzon suggest the more modern hominin species, the Denisovans, also called the Philippine island home.
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. At the current rate, it's likely those questions will be complicated by new discoveries before paleontologists can devise sufficient answers.