An international team of researchers has discovered the 50,000 year-old remains of a previously unknown species of human in the Philippines. The new species has been named Homo luzonensis after Luzon Island, where the fossils were found in the Callao Cave.
The research supports the idea that this region played an important role in hominin evolutionary history. Study co-author Professor Philip Piper from The Australian National University (ANU) said the findings represent a major breakthrough in our understanding of human evolution across Southeast Asia.
The fossils, which were obtained from within the same archaeological deposits, belonged to at least two adults and one juvenile.
“The fossil remains included adult finger and toe bones, as well as teeth. We also recovered a child’s femur. There are some really interesting features – for example, the teeth are really small,” said Professor Piper.
“The size of the teeth generally, though not always, reflect the overall body-size of a mammal, so we think Homo luzonensis was probably relatively small. Exactly how small we don’t know yet. We would need to find some skeletal elements from which we could measure body-size more precisely.”
“It’s quite incredible, the extremities, that is the hand and feet bones are remarkably Australopithecine-like. The Australopithecines last walked the earth in Africa about 2 million years ago and are considered to be the ancestors of the Homo group, which includes modern humans.”
“So, the question is whether some of these features evolved as adaptations to island life, or whether they are anatomical traits passed down to Homo luzonensis from their ancestors over the preceding 2 million years.”
The origins of Homo luzonensis and their duration on the island of Luzon are not yet known. Recent excavations near Callao Cave produced evidence of a butchered rhinoceros and stone tools dating back about 700,000 years.
“No hominin fossils were recovered, but this does provide a timeframe for a hominin presence on Luzon. Whether it was Homo luzonensis butchering and eating the rhinoceros remains to be seen,” said Professor Piper said.
“It makes the whole region really significant. The Philippines is made up of a group of large islands that have been separated long enough to have potentially facilitated archipelago speciation. There is no reason why archaeological research in the Philippines couldn’t discover several species of hominin. It’s probably just a matter of time.”
There is evidence to suggest that Homo luzonensis may have inhabited many of the large islands of Southeast Asia. In addition, the remains share some unique skeletal features with the hobbit, or Homo floresiensis, which were found southeast of the Philippines on the island of Flores.
The study is published in the journal Nature.
By Chrissy Sexton, Earth.com Staff Writer
Image Credit: Callao Cave Research Project