An experimental investigation of cut mark production and stone tool attrition

Abstract In discussions of Paleolithic hominin behavior it is often assumed that cut marks are an unwanted byproduct of butchery activities, and that their production causes the dulling of stone tool edges. It is also presumed that Paleolithic butchers would have refrained from making cut marks to extend the use life of their tools. We conducted a series of butchery experiments designed to test the hypothesis that cut marks affect the use life of tools. Results suggest cut marks are not associated with edge attrition of simple flake tools, and therefore it is unlikely that Paleolithic butchers would have avoided contact between bone surfaces and tool edges. Edge attrition is, however, significantly greater during skinning and disarticulation than during defleshing. This suggests that skinning and disarticulation activities would require more tool edges relative to butchery events focused purely on defleshing. Differences between the number of cut-marked bones relative to the number of stone artifacts deposited at taphonomically comparable archaeological localities may be explicable in terms of different types of butchery activities conducted there, rather than strictly the timing of carcass access by hominins. Archaeological localities with higher artifact discard rates relative to raw material availability may represent an emphasis on activities associated with higher edge attrition (e.g. skinning or disarticulation)

Earliest archaeological evidence of persistent hominin carnivory

The emergence of lithic technology by ~2.6 million years ago (Ma) is often interpreted as a correlate of increasingly recurrent hominin acquisition and consumption of animal remains. Associated faunal evidence, however, is poorly preserved prior to ~1.8 Ma, limiting our understanding of early archaeological (Oldowan) hominin carnivory. Here, we detail three large well-preserved zooarchaeological assemblages from Kanjera South, Kenya. The assemblages date to ~2.0 Ma, pre-dating all previously published archaeofaunas of appreciable size. At Kanjera, there is clear evidence that Oldowan hominins acquired and processed numerous, relatively complete, small ungulate carcasses. Moreover, they had at least occasional access to the fleshed remains of larger, wildebeest-sized animals. The overall record of hominin activities is consistent through the stratified sequence ??? spanning hundreds to thousands of years ??? and provides the earliest archaeological evidence of sustained hominin involvement with fleshed animal remains (i.e., persistent carnivory), a foraging adaptation central to many models of hominin evolution.This research was supported by funding from the National Science Foundation, Leakey Foundation, Wenner-Gren Foundation, National Geographic Society, The Leverhulme Trust, University of California, Baylor University, and the City University of New York. Additional logistical support was provided by the Smithsonian Institution???s Human Origins Program and the Peter Buck Fund for Human Origins Research, the British Institute in Eastern Africa, and the National Museums of Kenya. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Earliest Archaeological Evidence of Persistent Hominin Carnivory

The emergence of lithic technology by ∼2.6 million years ago (Ma) is often interpreted as a correlate of increasingly recurrent hominin acquisition and consumption of animal remains. Associated faunal evidence, however, is poorly preserved prior to ∼1.8 Ma, limiting our understanding of early archaeological (Oldowan) hominin carnivory. Here, we detail three large well-preserved zooarchaeological assemblages from Kanjera South, Kenya. The assemblages date to ∼2.0 Ma, pre-dating all previously published archaeofaunas of appreciable size. At Kanjera, there is clear evidence that Oldowan hominins acquired and processed numerous, relatively complete, small ungulate carcasses. Moreover, they had at least occasional access to the fleshed remains of larger, wildebeest-sized animals. The overall record of hominin activities is consistent through the stratified sequence – spanning hundreds to thousands of years – and provides the earliest archaeological evidence of sustained hominin involvement with fleshed animal remains (i.e., persistent carnivory), a foraging adaptation central to many models of hominin evolution

Snapshots of human anatomy, locomotion, and behavior from Late Pleistocene footprints at Engare Sero, Tanzania

Fossil hominin footprints preserve data on a remarkably short time scale compared to most other fossil evidence, offering snapshots of organisms in their immediate ecological and behavioral contexts. Here, we report on our excavations and analyses of more than 400 Late Pleistocene human footprints from Engare Sero, Tanzania. The site represents the largest assemblage of footprints currently known from the human fossil record in Africa. Speed estimates show that the trackways reflect both walking and running behaviors. Estimates of group composition suggest that these footprints were made by a mixed-sex and mixed-age group, but one that consisted of mostly adult females. One group of similarly oriented trackways was attributed to 14 adult females who walked together at the same pace, with only two adult males and one juvenile accompanying them. In the context of modern ethnographic data, we suggest that these trackways may capture a unique snapshot of cooperative and sexually divided foraging behavior in Late Pleistocene humans

The Age of the 20 Meter Solo River Terrace, Java, Indonesia and the Survival of Homo erectus in Asia

Homo erectus was the first human lineage to disperse widely throughout the Old World, the only hominin in Asia through much of the Pleistocene, and was likely ancestral to H. sapiens. The demise of this taxon remains obscure because of uncertainties regarding the geological age of its youngest populations. In 1996, some of us co-published electron spin resonance (ESR) and uranium series (U-series) results indicating an age as young as 35–50 ka for the late H. erectus sites of Ngandong and Sambungmacan and the faunal site of Jigar (Indonesia). If correct, these ages favor an African origin for recent humans who would overlap with H. erectus in time and space. Here, we report 40Ar/39Ar incremental heating analyses and new ESR/U-series age estimates from the “20 m terrace" at Ngandong and Jigar. Both data sets are internally consistent and provide no evidence for reworking, yet they are inconsistent with one another. The 40Ar/39Ar analyses give an average age of 546±12 ka (sd±5 se) for both sites, the first reliable radiometric indications of a middle Pleistocene component for the terrace. Given the technical accuracy and consistency of the analyses, the argon ages represent either the actual age or the maximum age for the terrace and are significantly older than previous estimates. Most of the ESR/U-series results are older as well, but the oldest that meets all modeling criteria is 143 ka+20/−17. Most samples indicated leaching of uranium and likely represent either the actual or the minimum age of the terrace. Given known sources of error, the U-series results could be consistent with a middle Pleistocene age. However, the ESR and 40Ar/39Ar ages preclude one another. Regardless, the age of the sites and hominins is at least bracketed between these estimates and is older than currently accepted

Evidence of artefacts made of giant sloth bones in central Brazil around the last glacial maximum

International audienceThe peopling of the Americas and human interaction with the Pleistocene megafauna in South America remain hotly debated. The Santa Elina rock shelter in Central Brazil shows evidence of successive human settlements from around the last glacial maximum (LGM) to the Early Holocene. Two Pleistocene archaeological layers include rich lithic industry associated with remains of the extinct giant ground sloth Glossotherium phoenesis . The remains include thousands of osteoderms (i.e. dermal bones), three of which were human-modified. In this study, we perform a traceological analysis of these artefacts by optical microscopy, non-destructive scanning electron microscopy, UV/visible photoluminescence and synchrotron-based microtomography. We also describe the spatial association between the giant sloth bone remains and stone tools and provide a Bayesian age model that confirms the timing of this association in two time horizons of the Pleistocene in Santa Elina. The conclusion from our traceological study is that the three giant sloth osteoderms were intentionally modified into artefacts before fossilization of the bones. This provides additional evidence for the contemporaneity of humans and megafauna, and for the human manufacturing of personal artefacts on bone remains of ground sloths, around the LGM in Central Brazil

Evolution Education is a Complex Landscape

Researchers in various contexts have long struggled with an apparent disconnect between an individual’s level of understanding of biological evolution and their acceptance of it as an explanation for the history and diversity of life. Here, we discuss the main factors associated with acceptance of evolution and chart a path forward for evolution education research

Faunal and lithic inventory.

<p>NISP (number of identified specimens) and MNI (minimum number of individuals) are defined and quantified following the literature <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Lyman1" target="_blank">[43]</a>. ‘Total NISP’ reflects the sum of specimens recovered with coordinate data and included in this study. Tens of thousands of non-identifiable bone and tooth fragments <2 cm are omitted from this study. Fossils from conglomeratic facies (CP levels) are poorly preserved <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Plummer2" target="_blank">[49]</a>, and are likewise excluded from this study: KS-2CP (n = 259), KS-3CP (n = 102). Macro-mammals are defined here as weighing >5 kg. Macro-mammal NISP values are total sums and, in parentheses, the sum of specimens identified beyond Linnean class. %NISP and %MNI include macro-mammals only. Faunal and lithic counts are from the literature <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Ferraro1" target="_blank">[17]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Braun4" target="_blank">[55]</a>.</p

Skeletal element representation for (A) small and (B) medium-sized bovids, Bed KS-1.

<p>Abundance data presented as percent minimum animal units (%MAU), calculated following the literature <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Lyman1" target="_blank">[43]</a>. KJS data derived from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174.s003" target="_blank">Table S3</a>. 100% MAU = 6 for small bovids, 9 for medium-sized bovids. Similar patterns of skeletal element representation are present in Beds KS-2 and KS-3.</p