An international team of scientists has unearthed 57 stone tools and butchered animal bones at Kalinga in the Cagayan Valley of northern Luzon, the largest and most northerly island in the Philippines.
Along with an almost complete skeleton of extinct Rhinoceros philippinensis, showing clear signs of having been butchered, the team unearthed six cores, 49 flakes and two possible hammer stones.
Several of Rhinoceros philippinensis bones had cut marks and the left and right humerus bones showed signs of being hit with hammer stones, possibly to gain access to the marrow. Other fossils found at the Kalinga site included stegodon, Philippine brown deer, freshwater turtle and monitor lizard.
The fossils and stone tools were found in a clay bed dated to between 777,000 and 631,000 years ago.
This conclusion was reached by combining several dating methods, confirming that the butchering of the rhino took place around 700,000 years ago.
“The Kalinga finds change our understanding of hominin colonization of the Philippines,” the researchers said.
“The earliest evidence of hominins in the area prior to this research was a 67,000-year-old foot bone found in nearby Callao Cave.”
The finds suggest the dispersal of premodern hominins through the region took place several times, and that the Philippines may have played a central role.
“It was most likely that these early humans spread through Island South East Asia from north to south — with Luzon as one of the stepping stones — following the ocean currents south and eventually reaching Flores to give rise to the ancestral population that led to Homo floresiensis,” said team member Dr. Gerrit van den Bergh, a researcher with the Centre for Archaeological Science at the University of Wollongong, Australia.
“Our hypothesis is that Homo floresiensis ancestors came from the north, rather than traveling eastward through Java and Bali.”
Until recently, it was believed Luzon and the other islands of Wallacea (those islands east of the Wallace Line, separated from the rest of Asia and from Australia by deep water) could not have been reached by premodern hominins as it was assumed they didn’t have boats (islands west of the Wallace Line were joined to the mainland when sea levels were lower).
However, the discovery of Homo floresiensis on the Indonesian island of Flores in 2003 and more recent discoveries on neighboring Sulawesi show that hominins were in Wallacea from very early on.
Recently uncovered evidence shows the ancestors of Homo floresiensis were on Flores by 700,000 years ago, around the same time hominins were present on Luzon.
“The dispersal of fauna through the Wallacean islands supports the theory of hominin colonization from the north,” Dr. van den Bergh said.
“If you look at the fossil and recent faunas you see that there is an impoverishment as you go from north to south: (i) on Luzon you find fossils of stegodons, elephants, giant rats, rhino, deer, large reptiles and a type of water buffalo; (ii) on Sulawesi, the fossil fauna is already impoverished; there’s no evidence of rhinos or deer ever entering there; (iii) then on Flores, you only had stegodons, Komodo dragons, humans and giant rats, that’s all.”
“If animals did reach these islands by chance, by entering the sea and following the currents south, then you would expect the further south you go the fewer species you would find — and that’s what we see.”
While it’s possible, if unlikely, that the first human colonizers of the Philippines were able to construct simple rafts, the team believes they more likely arrived by accident.
“They may have been caught in a tsunami and carried out to sea — those kinds of freak, random events are probably responsible for these movements of humans and animals,” Dr. van den Bergh said.
“This region is tectonically active so tsunamis are common and there are big ones every hundred years or so.”
Aside from the fact they made stone tools, the scientists know very little about the people who butchered Rhinoceros philippinensis at Kalinga.
“They were probably closely related to Homo erectus, and most likely the ancestors of the human found in Callao Cave — modern humans aren’t believed to have arrived in the Philippines until around 50,000 years ago,” Dr. van den Bergh said.
The team’s results appear in the journal Nature.
T. Ingicco et al. Earliest known hominin activity in the Philippines by 709 thousand years ago. Nature, published online May 2, 2018; doi: 10.1038/s41586-018-0072-8
Source link: https://www.sci.news/archaeology/archaic-hominins-philippines-05980.html