High-tech tackle, scale bar: 1 centimetre per square (Image: J. Erlandson)

A treasure trove of finely crafted fishing spearheads from 12,000 years ago has been discovered on the Channel Islands of California. They are a clue to the lifestyles of some of the earliest American settlers, and suggest that two separate cultures lived in North America at the time: one, the well-known Clovis culture, lived inland and feasted on mammoths, mastodons and other mammals; the other was a coastal culture with a taste for seafood.

The archaeologists who made the find believe that the two groups were distinct, but shared trade links.

Jon Erlandson of the University of Oregon in Eugene and his team poked around caves, springs and likely sites of ancient human settlement on the islands of Santa Rosa and San Miguel, and found more than 50 shell middens – large trash heaps of discarded seashells, chipped stone tools and animal bones – which they dated to between 10,000 and 12,000 years ago.


They think that during this period early Americans used the islands for seasonal hunting camps, most likely in the winter when fresh water would have been plentiful. The remains suggest that early colonisers hunted birds such as overwintering Canada geese, snow geese, albatross and cormorants – and possibly marine mammals like otters and seals – but also harvested a variety of shellfish from kelp forests, including mussels, red abalone and crabs.

Such a diet contrasts with the big-game hunters who lived on the mainland at the time and liked to chase camels, horses and mastodons.

Delicate work

But what astonished Erlandson and his colleagues were the tools they found near the middens.

Team member Todd Braje of Humboldt State University in Arcata, California, describes finely crafted barbed spearheads. “We found very thin, expertly made projectile points and it blew us away that these delicate flint-knapped points are this old,” he says. Such tools are generally only found at more recent sites.

These fine, barbed points are markedly different from those previously found at Clovis sites, which tend to be simple, fluted points. This hints at the coexistence of two separate groups of people in North America at the time.

However, Loren Davis of Oregon State University in Corvallis points out that the team also found Clovis-like spearheads on the islands: he says that tools he has dug up on the North American mainland look nearly identical to some of the ones Erlandson and his team found.

“That means peoples on the Channel Islands and people in western Idaho, for example, were at one point exposed to the same ideas about how to make technology,” Davis says. A likely explanation is that the two groups shared some kind of trade.

By land or sea?

That Erlandson and his teams found the remains on what was once a single island off the coast of modern-day California is also significant. There are many hypotheses for how humans colonised North America: one popular scenario is that they crossed over from Asia across a land bridge that once linked Siberia and Alaska.

But some historians believe at least some of the early settlers were seafarers, and either dropped down along the coast from Alaska or even crossed over from Japan. Erlandson and his colleagues say their new finds support the idea that the first people to inhabit the Americas were mariners, or perhaps that land and sea-based migrations occurred in tandem.

It’s too early to say for sure. Davis points out – and Braje concedes – that the Channel Island sites are not the oldest in the Americas, so they do not tell us about the very first pioneers. Still, Braje says, “this pushes back the chronology of New World seafaring to 12,000, maybe 13,000 years ago. It gets us a big step closer to showing that a coastal migration route happened, or was at least possible.”

Journal reference: Science, DOI: 10.1126/science.1201477