Mal'ta Boy (ANE): Origins of Native Americans

A startling new report asserts that the first known Americans arrived much, much earlier than scientists thought — more than 100,000 years ago __ and maybe they were Neanderthals.

If true, the finding would far surpass the widely accepted date of about 15,000 years ago.

Researchers say a site in Southern California shows evidence of humanlike behavior from about 130,000 years ago, when bones and teeth of an elephantlike mastodon were evidently smashed with rocks.



The earlier date means the bone-smashers were not necessarily members of our own species, Homo sapiens. The researchers speculate that these early Californians could have instead been species known only from fossils in Europe, Africa and Asia: Neanderthals, a little-known group called Denisovans, or another human forerunner named Homo erectus.

“The very honest answer is, we don’t know,” said Steven Holen, lead author of the paper and director of the nonprofit Center for American Paleolithic Research in Hot Springs, South Dakota. No remains of any individuals were found.



Whoever they were, they could have arrived by land or sea. They might have come from Asia via the Beringea land bridge that used to connect Siberia to Alaska, or maybe come across by watercraft along the Beringea coast or across open water to North America, before turning southward to California, Holen said in a telephone interview.

Some archaeologists, however, maintain that humans arrived earlier. They point to sites containing rocks that resemble stone tools as well as large animal bones that have damage apparently inflicted by humans. Deméré's co-authors Kathleen Holen and her husband Steven Holen, archaeologists at the Center for American Paleolithic Research in Hot Springs, South Dakota, have put forward several sites in the US Midwest as evidence for a human presence in the Americas up to 40,000 years ago3. But many scientists have viewed these claims with scepticism.





After hearing about the San Diego mastodon, the Holens visited Deméré in 2008 to see the boxed-up remains. “We were looking at something very, very old, but it had the same fracture patterns that we had seen before,” says Kathleen Holen. The bones looked as though they had been set on by a large ‘anvil’ stone and struck with a ‘hammer’ rock. The team contends that the rocks recovered from the site were used either to extract the mastodon’s bone marrow or for making more-delicate bone tools. There are no obvious cut marks on the mastodon bone, suggesting that the animal wasn’t killed or butchered for its meat.

Using refined dating methods, the researchers tried again to determine the age of the site. They couldn’t use radiocarbon dating on the mastodon remains because the bones lacked carbon-containing collagen protein. A second method was too imprecise. A third technique, which measures relative levels of radioactive uranium and thorium in bone, suggested that the remains are 130,000 years old. “I’m sure that many of our colleagues are going to be quite sceptical. I would expect that. This is far, far older than most archaeologists expect hominins to be in North America,” says Steven Holen. “I say that even for myself.”



The earliest dispersal of humans into North America is a contentious subject, and proposed early sites are required to meet the following criteria for acceptance: (1) archaeological evidence is found in a clearly defined and undisturbed geologic context; (2) age is determined by reliable radiometric dating; (3) multiple lines of evidence from interdisciplinary studies provide consistent results; and (4) unquestionable artefacts are found in primary context1, 2. Here we describe the Cerutti Mastodon (CM) site, an archaeological site from the early late Pleistocene epoch, where in situ hammerstones and stone anvils occur in spatio-temporal association with fragmentary remains of a single mastodon (Mammut americanum). The CM site contains spiral-fractured bone and molar fragments, indicating that breakage occured while fresh. Several of these fragments also preserve evidence of percussion. The occurrence and distribution of bone, molar and stone refits suggest that breakage occurred at the site of burial. Five large cobbles (hammerstones and anvils) in the CM bone bed display use-wear and impact marks, and are hydraulically anomalous relative to the low-energy context of the enclosing sandy silt stratum. 230Th/U radiometric analysis of multiple bone specimens using diffusion–adsorption–decay dating models indicates a burial date of 130.7 ± 9.4 thousand years ago. These findings confirm the presence of an unidentified species of Homo at the CM site during the last interglacial period (MIS 5e; early late Pleistocene), indicating that humans with manual dexterity and the experiential knowledge to use hammerstones and anvils processed mastodon limb bones for marrow extraction and/or raw material for tool production. Systematic proboscidean bone reduction, evident at the CM site, fits within a broader pattern of Palaeolithic bone percussion technology in Africa3, 4, 5, 6, Eurasia7, 8, 9 and North America10, 11, 12. The CM site is, to our knowledge, the oldest in situ, well-documented archaeological site in North America and, as such, substantially revises the timing of arrival of Homo into the Americas.

Nature 544, 479–483 (27 April 2017)