Human Dental Microwear From Ohalo II (22,500–23,500 cal BP), Southern Levant

Dietary hardness and abrasiveness are inferred from human dental microwear at Ohalo II, a late Upper Palaeolithic site (22,500–23,500 cal BP) in the southern Levant. Casts of molar grinding facets from two human skeletons were examined with a scanning electron microscope. The size and frequency of microwear was measured, counted, and compared to four prehistoric human groups from successive chronological periods in the same region: pre-pottery Neolithic A, Chalcolithic (this study); Natufian, pre-pottery Neolithic B (Mahoney: Am J Phys Anthropol 130 (2006) 308–319). The Ohalo molars had a high frequency of long narrow scratches, and a few small pits, suggesting a tough abrasive diet that required more shearing rather than compressive force while chewing. These results imply that the diet of the two late Upper Palaeolithic hunter-gatherers did not focus on very hard foods. Aquatic foods with adherent contaminants, as well as grit from plant grinding tools seemed likely causal agents. The size of the pits and scratches on the Ohalo molars were most similar to microwear from the pre-pot- tery Neolithic A period, though they also compared well to the Chalcolithic period. These results contrasted with the larger pits and scratches from the Natufian hunter-gath- erers and pre-pottery Neolithic B farmers, implying that there is no simple increase or decrease in dietary hard- ness and abrasiveness across the late Upper Palaeolithic to Chalcolithic development in the Southern Levant

The ATLAS Experiment at the CERN Large Hadron Collider

The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented