Photos: Speared Mastodon Bone Hints at Earlier Americans

Bone Deep
Diagram courtesy Science/AAAS
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.)
—Brian Handwerk
Published October 21, 2011
Angle of Attack
Illustration courtesy Texas A&M University
A mastodon illustration shows the angle at which ancient hunters drove a spear point through some 10 to 12 inches (25 to 30 centimeters) of hide, tissue, and muscle before penetrating bone.
Experts say the kill greatly predates the emergence of the Clovis culture.
"This is a kill site where we have solid dating, geological context, artifacts, and other evidence showing that people were here almost a millennium before Clovis," study leader Waterssaid.
Combined with evidence from prehistoric hunting camps in what's now Wisconsin—including butchering tools and mammoth remains—the speared bone supports a theory that Native Americans were hunting mastodons and mammoths at least 2,000 years before the Clovis culture arose, around 13,000 B.C., he said.
(Related: "Oldest American Art Found on Mammoth Bone.")
Published October 21, 2011
Before the Fall
Illustration by Charles R. Knight, National Geographic
North America's mastodons (file illustration) went extinct about 12,800 years ago. Climate change and disease may have been causes, but Clovis hunters have also borne a big share of the blame. (See pictures of a nearly perfectly preserved mammoth baby.)
A "blitzkrieg" theory suggests Clovis groups poured south through an ice-free corridor in western Canada, armed themselves with pointed stone weapons, and killed off big game in relatively short order.
But recent evidence, such as the speared mastodon rib from Washington State, hints at previous human pressure on the elephant-like creatures.
"I think Manis, as well as the Wisconsin sites, shows that people were hunting these elephants a long time before Clovis," Waters said. "Granted, the climate was changing, and the vegetation was changing, but they were also being hunted, and that probably had some impact on their populations."
(Related: "Mastodons Driven to Extinction by Tuberculosis, Fossils Suggest.")
Published October 21, 2011
Davids and Goliath
Illustration by Roy Andersen, National Geographic
Native Americans hunt mastodon with spears around 11,000 B.C. (file illustration).
The newly analyzed bone projectile point is the first known weapon to be associated with a pre-Clovis kill site, Waters said.
"We've seen stone tools probably used in the butchering of mammoths, but not any kinds of projectiles that would have been used to bring them down."
(Related: "Americas Settled by Two Groups of Early Humans, Study Says.")
Published October 21, 2011
Bone in Bone
Image courtesy Texas A&M University
A CT scan reveals a cross-section of a nearly 14,000-year-old injury—the broken bone tip of a spear embedded in the rib of an ancient mastodon. The point, itself made of mastodon bone, is about the same size as the tips of the throwing or thrusting weapons later developed by the Clovis people.
Along with other evidence from hunting and butchering sites, the rib suggests an earlier origin for bone, ivory, antler, and stone points in North America—a birth date more in line with what DNA studies are telling us about the advent of the continent's peopling, Waters said.
"All the technologies that you'd need to eventually evolve into the Clovis culture were present in North America long before Clovis," he said—which suggests the Clovis didn't migrate from elsewhere but rather arose from those who came before.
More: "Clovis People Not First Americans, Study Shows" >>
Published October 21, 2011