Homo Luzonensis: New Human Species Found in Luzon

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Homo Luzonensis: New Human Species Found in Luzon Apr 10, 2019 18:45:36 GMT

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Post by Admin on Apr 10, 2019 18:45:36 GMT

Scientists have found a few bones and seven teeth belonging to a previously unknown species of human. They've named the new species Homo luzonensis, after the island of Luzon in the Philippines where it was found. The bones are tiny, suggesting that Homo luzonensis was under 4 feet tall.

That would make it the second species of diminutive human to be found in south-east Asia; in 2007 scientists announced the discovery of Homo floresiensis, found on the island of Flores in Indonesia and nicknamed the hobbit. Both species lived around 50,000 years ago, at a time when Asia was also home to our species, the Neanderthals and a group called the Denisovans. The new species raises many questions, including who were its ancestors and how did it move?

Humankind's tangled shrub of ancestry now has a new branch: Researchers in the Philippines announced today that they have discovered a species of ancient human previously unknown to science.

The small-bodied hominin, named Homo luzonensis, lived on the island of Luzon at least 50,000 to 67,000 years ago. The hominin—identified from a total of seven teeth and six small bones—hosts a patchwork of ancient and more advanced features. The landmark discovery, announced in Nature on Wednesday, makes Luzon the third Southeast Asian island in the last 15 years to bear signs of unexpectedly ancient human activity.

“For a long, long time, the Philippine islands [have] been more or less left [out]," says study coauthor and project leader Armand Mijares, an archaeologist at the University of the Philippines Diliman and a National Geographic grantee. But H. luzonensis flips the script, and it continues to challenge the outdated idea that the human line neatly progressed from less advanced to more advanced species.

That all changed in 2004, when researchers unveiled Homo floresiensis—a diminutive hominin, also known as the “hobbit,” that inhabited the Indonesian island of Flores until 50,000 years ago. Inspired, Mijares returned to Callao Cave in 2007 to literally dig deeper.

The team excavated more than five feet of clay below where they had stopped digging in 2003, with no fossils in sight. But then they found a layer of breccia, a type of rock formed from a jumble of other materials. Tantalizingly, this layer contained fragments of bone that had washed into the cave long ago. At first, the bones seemed to include only animals such as deer and pigs. But under closer inspection, one piece stood out: a nearly complete foot bone that looked human. The team sent the fossil to Philip Piper, a coauthor of the new study, who was looking through the animal remains.

In 2010, Mijares and his colleagues unveiled the 67,000-year-old fossil, which they tentatively suggested belonged to a small-bodied member of Homo sapiens, making it perhaps the oldest sign of our species anywhere in the Philippines at the time. But Mijares suspected that it might actually belong to a new species, maybe even a Luzon analog to H. floresiensis. The team needed more fossils to be sure.

Raft of possibilities
While evolution sculpted H. luzonensis into a small form similar to that of H. floresiensis, we don't know which island conditions drove the differences between the two species. Also, while a barrage of studies makes clear that interspecies unions happened regularly, we don't know whether H. luzonensis ancestors interacted or bred with other hominin species that lived in Asia at the time, such as the enigmatic Denisovans.

Another major unknown is how the ancestors of H. luzonensis even reached the Philippines. In 2016, researchers unveiled stone tools on the Indonesian island of Sulawesi that date to between 118,000 and 194,000 years old—or at least 60,000 years older than the island's oldest known modern humans. Taken alongside the remains from Flores and Luzon, the sites suggest that ancient hominin dispersal throughout the region wasn't necessarily as rare—or as accidental—as researchers once thought.

One thing remains clear: Southeast Asia probably was home to more hominin species than current fossils let on. For his part, Mijares is continuing to look for other signs of H. luzonensis, including a current search at Luzon's Biak na Bato National Park, done with support from the National Geographic Society. Through it all, Mijares sees the future for H. luzonensis—and for Asian anthropology—as bright.

Last Edit: Apr 23, 2019 17:45:58 GMT by Admin

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Homo Luzonensis: New Human Species Found in Luzon Apr 11, 2019 17:51:50 GMT

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Post by Admin on Apr 11, 2019 17:51:50 GMT

The oldest known Homo sapiens remains, found nearby on Palawan Island, were dated to 30,000 to 40,000 years ago. But this mysterious foot is older, dated to 67,000 years ago.

"It is the earliest hominin ever found in the Philippines," archaeologist Florent Détroit from the Muséum National d'Histoire Naturelle, in France, told ScienceAlert.

Now, an international team uncovered twelve other bits of ancient humans, in the same layer of rock where the foot bone was found. These include more foot bones, hand bones, a partial femur and teeth, thought to belong to at least three individuals - two adults and a child.

Détroit explained how the fossils are familiar, yet different to our bones and other known human species. Their premolar teeth have traits seen in Australopithecus and H. erectus, but their molars, while smaller, have a shape more similar to those found in H. sapiens.

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Homo Luzonensis: New Human Species Found in Luzon Apr 23, 2019 17:44:13 GMT

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Post by Admin on Apr 23, 2019 17:44:13 GMT

According to the study co-author, Prof Philip Piper from The Australian National University (ANU), this discovery offers a major breakthrough in our understanding of how humans evolved in Southeast Asia.

“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,” Piper said. “The size of the teeth generally, though not always, reflect the overall body-size of a mammal, so we think H. 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.”

There are still a lot of questions about the origins of H. luzonensis. But previous excavations near Callao Cave have revealed a butchered rhinoceros and ancient stone tools, dating back to 700,000 years ago.

“No hominin fossils were recovered, but this does provide a timeframe for a hominin presence on Luzon. Whether it was H. luzonensis butchering and eating the rhinoceros remains to be seen,” Prof Piper said.

Previous excavations in the Philippines have uncovered the famous 1.1-metre-tall H. floresiensis, also known as ‘the hobbit’, which was found on the island of Flores. Additionally, 200,000-year-old stone tools have been identified on Sulawesi, suggesting that ancient humans may have occupied large swathes of the region.

A hominin third metatarsal discovered in 2007 in Callao Cave (Northern Luzon, the Philippines) and dated to 67 thousand years ago provided the earliest direct evidence of a human presence in the Philippines. Analysis of this foot bone suggested that it belonged to the genus Homo, but to which species was unclear. Here we report the discovery of twelve additional hominin elements that represent at least three individuals that were found in the same stratigraphic layer of Callao Cave as the previously discovered metatarsal. These specimens display a combination of primitive and derived morphological features that is different from the combination of features found in other species in the genus Homo (including Homo floresiensis and Homo sapiens) and warrants their attribution to a new species, which we name Homo luzonensis. The presence of another and previously unknown hominin species east of the Wallace Line during the Late Pleistocene epoch underscores the importance of island Southeast Asia in the evolution of the genus Homo.

Naturevolume 568, 181–186 (2019)