A newly analyzed mastodon rib bone shows that Native Americans were using bone-pointed weapons to take down big game nearly a thousand years earlier than thought, according to a new study.
Images of the rib in close-up (A) and as a whole (D) show a broken projectile point still stuck where a hunter drove it in 13,800 years ago. The weapon, also made of bone, can be seen in a digital reconstruction (B) and an x-ray image (C).
The rib was found near Manis, Washington State, in the late 1970s and has been an object of debate ever since. Radiocarbon analysis, DNA samples, genetics work, and other modern techniques recently revealed its true age, according to the study, published Friday in the journal Science.
The age of the rib could help rewrite human history in the Americas, where the first well-established culture has been thought to be the Clovis people, named for finds near Clovis, New Mexico.
"We're starting to put together kill sites, camp sites—the whole gamut of the kinds of sites you'd expect to find that show pre-Clovis people were" in North America, said study leader Michael Waters, director of Texas A&M University's Center for the Study of the First Americans.
"If you take these sites together, and also look at the modern genetic evidence we have, it starts pointing toward a story that suggests people entered what's now the Lower 48 United States around 15,000 years ago—well before Clovis."
(Read a National Geographic magazine story on the peopling of the Americas.)