On May 2, archaeologists revealed that early humans inhabited the Philippines 700,000 years ago. Previous research indicated that humans were only there 67,000 years ago.

What Was Discovered

Scientists recently excavated an archaeological site on the island of Luzon in the Philippines. This is the largest island in the Philippines, and it is the 15th largest island in the world.

The excavations, which were in the Kalinga province, uncovered 400 animal bones and 57 stone tools. Researchers determined that the bones belonged to a deer, freshwater turtles, and stegodons. Along with the recently discovered bones was 75 percent of a fossilized skeleton of a slaughtered rhinoceros. There were also several cuts on the skeleton.

Using electron spin resonance, the researchers determined that the rhinoceros was killed 709,000 years ago. Since the researchers believed that a human killed the rhinoceros, this means humans were in the Pihllippines at the same time.

Researchers published their findings in the journal Nature on May 2.

What This Means

Scientists previously believed that humans inhabited the Philippines only 67,000 years ago because of a single bone found in a cave in Luzon. Archaeologists discovered other bones and tools throughout the decades, but they lacked the technology to properly date the objects.

"First is the very old age of this site which multiplies by ten the formerly known early presence of Hominins in the Philippines," said study author Thomas Ingicco, associate professor at the Muséum National d'Histoire Naturelle. "Second is the evidence for colonization of an ever-isolated island in The Philippines by the early Middle Pleistocene and therefore most likely by a hominin species other than Homo sapiens."

One question that scientists have not determined yet is how the early humans traveled to this island. Susan Antón, a paleoanthropologist at New York University, hypothesized that tsunami waves carried the early humans there.

How They Dated This

Determining the age of the rhinoceros was not an easy task because part of the skeleton was missing. Scientists used a combination of enamel from the teeth and quartz grains in the sediment to date it. With electron spin resonance, they calculated the buildup of electrons.

Although it was determined that humans did live in the Philippines over 700,000 years ago, there is still some uncertainty regarding which species of humans inhabited the land.

"The only thing missing is the hominin fossil to go along with it," said archaeologist Adam Brumm of Griffith University.

Homo sapiens likely didn't evolve until 300,000 years ago. Scientists believe that it was possibly H. erectus, an ancient species of humans that is extinct.