Neanderthals in California? Maybe so, provocative study says
- Author: Regina Walsh Апр 30, 2017,
Апр 30, 2017, 1:18
The fossil site was discovered by paleontologists with the San Diego Natural History Museum in 1992, however it wasn't until recently that they had the information and means required to accurately date their findings.
The researchers argue the stones might have been used as hammers and anvils to break the bones apart - meaning tool-users could have been spreading across the planet about six times earlier than we thought. "Currently the oldest widely accepted date of human presence in the new world is 14,000 to 15,000 years ago".
Then, in 2014, co-author James Paces, a researcher with the US Geological Survey, used state-of-the-art radiometric methods to measure traces of natural uranium and its decaying by-products in the mastodon bones, which were still fresh when broken by precise blows from stone hammers. Already, Smithsonian Magazine noted, the question of when humans arrived in North America is "a flashpoint among archaeologists".
They include Homo erectus, whose earliest traces date back almost two million years; Neanderthals, who fought and co-mingled with modern humans across Europe before dying out some 40,000 years ago; and an enigmatic species called Denisovans, whose DNA survives today in Australian aboriginals.
"Since the original discovery, dating technology has advanced to enable us to confirm with further certainty that early humans were here significantly earlier than commonly accepted", Demere said. For one thing, evidence suggests that the tools were only used for breaking bones, and not for extracting meat. It could not have been the work of carnivorous predators that broke the mastodon's bones.
Digital 3-D models of a selection of specimens pointing toward human association at this site can be viewed interactively at the University of Michigan Online Repository of Fossils (umorf.ummp.lsa.umich.edu). "This is important to paleontologists and archaeologists because they are analyzing the breakage patterns on the bones to find out if humans were associated with the mastodons", Beeton explained.Читайте также: Prominent firm to defend 'Bachelor' star in Iowa crash case
The team discovered bones from a young adult male mastodon - tusks, molars, vertebrae, ribs, paw bones and more than 300 fragments - centered around a large cobble stone.
"This is the first time there's been a demonstrated archaeological site with all the bells and whistles", said Curtis Runnels, an archaeologist at Boston University who was not involved with the study, referring to the combination of several lines of evidence at the site. "It's very rare that you get that whole package together in one site", Fullagar said. The mastodon site is about much more than the animal life in the region one hundred and thirty thousand years ago.
The San Diego Natural History Museum announced the findings to the public on Wednesday. Dr. Rob Benson, Adams State professor of geology and earth sciences, assisted Beeton by running X-Ray Diffraction on soil samples in the university's Interdisciplinary STEM Laboratory, and by collaborating on thin section analysis.
The study is considered controversial among scientists, according to the Nature journal, largely because it "would force a dramatic rethink of when and how the Americas were first settled - and by who".
"This discovery is rewriting our understanding of when humans reached the New World", said Judy Gradwohl, president and CEOP of the San Diego Natural History Museum, which made the find and managed the excavation. He has also published articles in major global peer-reviewed journals such as Geoarchaeology and Quaternary Research.
Fossil bone and rock at the excavation site in San Diego.При любом использовании материалов сайта и дочерних проектов, гиперссылка на обязательна.
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