The first Americans may have had neighbors, according to a new study from University of Oregon and Oregon State University researchers published today in the journal Science. Based on ancient human waste discovered in caves in central Oregon, historians might have to rewrite our understanding of how humans populated North America.

An ancient culture called Clovis lived in America roughly 12-13,000 years ago, as archaeologists have located their distinctly made tools throughout North and South America. Clovis are likely partial ancestors of Native Americans. However, researchers debated whether other American tool-making cultures arrived on the continent independently or merely descended from Clovis.

New research demonstrates that Clovis couldn’t be the only tool-makers at that time. Another people with their own crafting technique lived here too — and may even have predated Clovis.

Everywhere humans go, they leave behind waste. Sometimes it’s trash — tools like spear tips get dropped or discarded. Other times it’s that other sort of waste: poop. Without indoor plumbing to flush it away, buried excrement dries into lumps called coprolites.

Archaeologists and anthropologists treasure both varieties of waste, inadvertent time capsules of our ancestors. “What archaeologists usually deal with is garbage,” said UO’s Dennis Jenkins, lead author on the study.

Among the best-known caches of artifacts from predecessors of Native Americans are the Paisley Caves in Oregon. UO’s Luther Cressman first excavated the caves in the 1930s, finding evidence of human occupation thousands of years prior but unable to precisely date his findings.

Paisley Caves was likely a temporary camping site for ancient hunters, explained Michael Waters of Texas A&M, who was not involved in the study but has visited the caves. After a day of hunting mountain sheep, antelope or possibly longhorn, people sought shelter in the caves to rest, repair their weapons and possibly even make a fire. After a short time, they moved on.

Many of Cressman’s contemporaries disbelieved his findings due to inadequate documentation. For the past decade, an international team led by University of Oregon and Oregon State University researchers has performed a more meticulous excavation.

READ THE FULL ARTICLE HERE: Ancient people discovered in Oregon may shake up understanding of 1st Americans | OregonLive.com.