World’s oldest stone tools challenge ideas about first toolmakers
Date: May 20, 2015
Source:The Earth Institute at Columbia University
Summary:
Scientists working in the desert of northwestern Kenya have found stone tools dating back 3.3 million years, long before the advent of modern humans, and by far the oldest such artifacts yet discovered. The tools push the known date of such tools back by 700,000 years; they also may challenge the notion that our own most direct ancestors were the first to bang two rocks together to create a new technology.
Scientists working in the desert badlands of northwestern Kenya have found stone tools dating back 3.3 million years, long before the advent of modern humans, and by far the oldest such artifacts yet discovered. The tools, whose makers may or may not have been some sort of human ancestor, push the known date of such tools back by 700,000 years; they also may challenge the notion that our own most direct ancestors were the first to bang two rocks together to create a new technology.
Excerpts:
The researchers do not know who made these oldest of tools. But earlier finds suggest a possible answer: The skull of a 3.3-million-year-old hominin, Kenyanthropus platytops, was found in 1999 about a kilometer from the tool site. A K. platyops tooth and a bone from a skull were discovered a few hundred meters away, and an as-yet unidentified tooth has been found about 100 meters away
The precise family tree of modern humans is contentious, and so far, no one knows exactly how K. platyops relates to other hominin species. Kenyanthropus predates the earliest known Homo species by a half a million years. This species could have made the tools; or, the toolmaker could have been some other species from the same era, such as Australopithecus afarensis, or an as-yet undiscovered early type of Homo.
Lepre said a layer of volcanic ash below the tool site set a “floor” on the site’s age: It matched ash elsewhere that had been dated to about 3.3 million years ago, based on the ratio of argon isotopes in the material. To more sharply define the time period of the tools, Lepre and co-author and Lamont-Doherty colleague Dennis Kent examined magnetic minerals beneath, around and above the spots where the tools were found.
So, barring errors in the method of dating, this demonstrates a window of time to pinpoint a phenomenon toolmaking per archeological reckoning. This predates the Pre-Ancient Temples in Turkey by over 3.25 million years.
Which method of temporal dating is off (if any), and more importantly: How do we know?