A geometric morphometric relationship predicts stone flake shape and size variability

The archaeological record represents a window onto the complex relationship between stone artefact variance and hominin behaviour. Differences in the shapes and sizes of stone flakes—the most abundant remains of past behaviours for much of human evolutionary history—may be underpinned by variation in a range of different environmental and behavioural factors. Controlled flake production experiments have drawn inferences between flake platform preparation behaviours, which have thus far been approximated by linear measurements, and different aspects of overall stone flake variability (Dibble and Rezek J Archaeol Sci 36:1945–1954, 2009; Lin et al. Am Antiq 724–745, 2013; Magnani et al. J Archaeol Sci 46:37–49, 2014; Rezek et al. J Archaeol Sci 38:1346–1359, 2011). However, when the results are applied to archaeological assemblages, there remains a substantial amount of unexplained variability. It is unclear whether this disparity between explanatory models and archaeological data is a result of measurement error on certain key variables, whether traditional analyses are somehow a general limiting factor, or whether there are additional flake shape and size drivers that remain unaccounted for. To try and circumvent these issues, here, we describe a shape analysis approach to assessing stone flake variability including a newly developed three-dimensional geometric morphometric method (‘3DGM’). We use 3DGM to demonstrate that a relationship between platform and flake body governs flake shape and size variability. Contingently, we show that by using this 3DGM approach, we can use flake platform attributes to both (1) make fairly accurate stone flake size predictions and (2) make relatively detailed predictions of stone flake shape. Whether conscious or instinctive, an understanding of this geometric relationship would have been critical to past knappers effectively controlling the production of desired stone flakes. However, despite being able to holistically and accurately incorporate three-dimensional flake variance into our analyses, the behavioural drivers of this variance remain elusive.     

Reappraisal of ‘chronospecies’ and the use of Arvicola (Rodentia,Mammalia) for biochronology

The water vole, genus Arvicola, is characterised by a broad geographic distribution throughout Europe and is widespread during the late Middle and Upper Pleistocene. This genus is used as a major biostratigraphic tool within the Quaternary. Specific determinations using the Schmelzband-Differenzierung-Quotient or SDQ have identified many chronospecies within the fossil species Arvicola cantiana (Hinton, 1910). As SDQ calculation remains limited, this study reappraises the Arvicola genus in terms of morphodiversity and morphospace using outline analysis which takes into account the tooth as a whole. Outline analysis suggests that one single species of Arvicola, A. cantiana, was present during the Pleistocene. This species shows great variability with no trends or patterns in morphospace. Thus, these results call into question the reliability of SDQ for specific determinations and throw doubt on the biochronological framework based on Arvicola.     

Le Grand Abri aux Puces,a Mousterian site from the Last Interglacial: paleogeography,paleoenvironment, and new excavation results

Le Grand Abri aux Puces (GAP), located on the right bank of the Ouvèze River of southern France, has been known to contain well-preserved stone tools and faunal remains, but our work in 2008 was the first professional, controlled excavation at the site and has exposed at least 1 archaeological layer with a very rich and diverse faunal assemblage (23 macrofaunal species, as many for the microfauna, 27 land snail species), abundant charcoals (fragments are large and preserve small twigs with their pith and bark still intact), and stone tools with immaculate surface preservation (retaining their original freshness and preserving microscopic use wear). The information issuing from paleontology, micropaleontology, malacology, and anthracology all place the principle GAP human occupation unambiguously in a temperate climatic phase. Different biometric and biochronological characters of the fauna converge to place the layers found thus far from before the last glacial, and most likely in MIS 5e (127–117 kya). The lithic elements, mainly composed of tools of superior quality, demonstrating particular technical investment, and made from widely distributed raw material sources, lead us to hypothesize brief passages of hunting groups in the cave focused around an anticipated activity. This hypothesis will be refined and tested during further excavations.     

Pre-Clovis in Texas? A critical assessment of the “Buttermilk Creek Complex”

Lithic artifacts from the lowest strata of the Debra L. Friedkin site, located on Buttermilk Creek in central Texas, have been interpreted as an undisturbed pre-Clovis assemblage (Waters et al., 2011a). Stone tools and debitage were recovered from sediments stratified just below diagnostic Clovis artifacts and dated by OSL to between 13.2 and >15.5 cal kya. Invoking commonly observed cultural and natural site formation processes, we offer an alternative explanation of the “Buttermilk Creek Complex” as a Clovis assemblage in secondary association with the dated sediments.