Taphonomic analysis of rodent bone accumulations produced by Geoffroy's cat (Leopardus geoffroyi, Carnivora,Felidae) in Central Argentina

Rodent prey remains recovered from Geoffroy's cat (Leopardus geoffroyi) scats were analyzed in order to identify taphonomic features produced by this predator. The analysis includes a year-long sampling discriminated by the seasons. Modifications produced by digestion are heavy. Taphonomic variables in samples discriminated by the seasons did not show major differences with respect to the total sample; thus, scats collected in any season clearly show the modifications on the bones of prey rodents made by Geoffroy's cats. The results presented here and its interpretation could be extrapolated to an analysis of zooarchaeological or paleontological assemblages.     

Autochthony and orientation patterns in Olduvai Bed I: a re-examination of the status of post-depositional biasing of archaeological assemblages from FLK North (FLKN)

Recent excavations at FLK North (Olduvai Gorge, Tanzania) have produced new information on the orientation of archaeological materials at various levels of the site. This information includes the uniform distribution of material azimuths, which contrasts with previous inferences of highly patterned orientations of materials in the Bed I archaeological sites. Those previous inferences of patterned material orientations are based on Mary Leakey's 50-year-old drawings of artifact and fossil bone distribution, but are not verified by our precise measurements of archaeological objects made in situ. Nor do those previous results agree with the general lack of geological, geomorphological, and/or taphonomic data that would indicate significant post-depositional movement of archaeological materials in the sites. We argue here that Leakey's drawings are incomplete (only portions of each assemblage were drawn) and inaccurate in their representation of the original locations, shapes and orientations of most archaeological specimens. This argument is supported by several important mismatches in object representations between a photograph taken of a small portion of the FLK 22 Zinjanthropus site floor before the removal of the archaeological items, and the sketch of the same area drawn by Leakey. Thus, we conclude that primary orientation data of excavations (i.e., direct measurements taken from items) generated prior to object removal are the only valid indicators of the relative isotropy or anisotropy of these important paleoanthropological assemblages.     

Stable isotopes,diet, and taphonomy: a look at using isotope-based dietary reconstructions to infer differential survivorship in zooarchaeological assemblages

Archaeology has always faced the problem of making informed inferences based on an incomplete record. Zooarchaeological studies of prehistoric hunting and diet offer a clear case in point, where a range of behavioral and taphonomic factors can produce a substantial disconnect between what people actually captured and ate and what archaeologists recover and interpret. We explore this disconnect by presenting stable C and N data for wild faunas, archaeological maize, and three human burials from Fremont-period sites in southeastern Utah, the United States. We use these data to estimate faunal contributions to prehistoric diets and compare the results with previous zooarchaeological analyses of faunas from the same sites. Results for the two approaches differ sharply, with isotopic estimates showing much higher contributions of small and lowland game. We discuss these results in terms of both local prehistory and wider issues of taphonomy and dietary analysis.     

Charcoal scarcity in Epigravettian settlements with mammoth bone dwellings: the taphonomic evidence from Mezhyrich (Ukraine)

Fuel management during the Paleolithic periods is an important issue to understand past human subsistence. Numerous Palaeolithic sites relate an abundance of burnt bones in hearths and an absence or scarcity of wood charcoals, which leads studies to focus on burnt bone remains and the use of bones in hearths. Few works take into account the micro-residues of wood charcoals which can still be present in hearth areas and excavated sediments. We studied the Epigravettian site with mammoth bone dwellings of Mezhyrich (Ukraine) previously characterized by its high content of burnt bones and an “absence” of wood charcoal during the so-called mammoth steppe. The presence or absence and proportions of both wood charcoals and burnt bones were quantified in macro-, meso- and microscale sediment size fractions by an image analysis method. Our results show that excavations during field-works at Mezhyrich give only a partial image of the original anthracological record and that most charcoal materials are lost with standard archaeological and anthracological approaches. The scarcity of charcoals in this site was possibly due to an important mass reduction accentuated by the addition of bones in hearths. By applying our protocol we recovered a significant amount of wood charcoals which provides the first ¹⁴C dates from charcoals at Mezhyrich. Numerous charcoals are identified contributing subsequent information about vegetation, environment and burning practices. They indicate, by comparison with pollen data already collected, the presence of forest patches in a mammoth steppe landscape, which might have influenced the collecting behavior of Epigravettian populations.     

Carcass damage and digested bone from mountain lions (Felis concolor): implications for carcass persistence on landscapes as a function of prey age

This actualistic study examines the taphonomic signatures of modern free-ranging mountain lions (Felis concolor) on prey skeletal remains left at kill sites and digested bone fragments in the lions’ scats. Conducted in western Texas and southeastern New Mexico (U.S.A.), the study and its outcomes are relevant to models of carcass persistence and scavenging opportunities on ancient landscapes. Mountain lions in the study area ingested disproportionate quantities of bone from very young prey. This tendency holds true irrespective of prey body size. The results meanwhile confirm a relatively mild pattern of damage to adult deer carcasses. Digestive erosion of the surfaces of bones that passed through the gut was relatively severe, but many of these bone and tooth specimens retained identifiable features. It is clear that the mountain lions quickly remove the carcasses of very young prey from the pool of potentially scavenge-able resources. The non-linear relation between bone destruction from feeding by the cats and the skeletal maturity of prey also has consequences for prey mortality patterns, specifically a bias against the representation of very young individuals. This effect is not sufficient, however, to produce a global bias to prime-adult prey because older juveniles are much less affected.     

Taphonomy and sample size estimation in paleoethnobotany

This paper investigates how to gain quantitative comparability of macroscopic plant remains by estimating sample sizes representative to each population. First, this study reviews taphonomic pathways of plant remains to clarify how far we can draw cultural implications from the retrieved remains. The target population is defined here as the deposited assemblage, that is, plants that were deposited into the soil matrix. Through time, the deposited assemblage becomes reduced to the fossil assemblage, which is subject to being sampled (sampled population). The relation between the sampled population and samples is a statistical issue. A systematic recovery and a well-designed sampling strategy can help maintaining the same degree of representativeness of samples to the sampled population. The paper thus focuses on a statistical measure that estimates the sample sizes, based on a relative error and a confidence level of a small number of pilot samples. Data for the test is the plant remains recovered from the Nam River sites in south-central Korea, dating to the Early and Middle Mumun periods (3400-2400 BP). This measure ensures that quantitative differences between the plant remains in the two samples were due to real differences between the populations from which they were drawn rather than due only to variation within a single population. Thus this method strengthens cultural interpretations on quantitative differences in plant remains.     

What goes in does not always come out: The impact of the ruminant digestive system of sheep on plant material,and its importance for the interpretation of dung-derived archaeobotanical assemblages

Abstract

On archaeological sites where livestock dung was a major fuel source, plant material that survives digestion intact may well be preserved in the remnants of dung-fuelled fires. Preserved plant remains which were derived from dung relate to the diet of animals, and thus provide a way of investigating the agro-pastoral economies of the past. In order to improve our understanding of the taphonomic processes to which plant material is exposed to during digestion, we applied archaeobotanical methods to the analysis of dung from sheep fed a known diet of cereal and wild plant material. Two clear patterns emerge from these investigations. First, cereal material (grain or chaff) survives digestion poorly and was rarely found in the dung analysed. Second, large proportions of seeds of various wild species survive digestion in an identifiable form, probably due to their small size and/or protective coating. These findings are crucial for reliable interpretation of dung-derived plant material in archaeological settings.     

Carnivore competition, bone destruction, and bone density

In carnivore-modified archaeofaunal assemblages it is important to evaluate the degree to which carnivores have overprinted hominin behavioral signals. To examine the signals of increased competition for discarded bone, we present controlled experimental data on 33 simulated archaeological sites subjected to secondary consumption by spotted hyenas. We examine the relationship between competition, as measured by controlled numbers of hyenas and limb bones, and resultant levels of destruction and correlations between long-bone portion survivorship and bone density. Our results indicate that levels of destruction are equivalent regardless of the numbers of hyenas or long-bones included in the experimental assemblages. Correlations between long-bone epiphyseal and near-epiphyseal portions and bone density, however, do provide an indication of the level of competition. Results from the experimental study are used to highlight divergent levels of carnivore competition for hominin-discarded bone at the Plio-Pleistocene localities FLKN-Zinjanthropus and FLKN levels 1–2 from Olduvai Gorge, Tanzania.     

Edge damage distribution at the assemblage level on Middle Stone Age lithics: an image-based GIS approach

Lithic artifacts represent the most abundant cultural remains from Middle Stone Age sites in southern Africa. Of these, pointed forms (under a variety of names), blades, and flakes have long been recognized as the three most abundant general types, and retouch on all three is rare relative to similar forms of equivalent age elsewhere. Here we offer a new technique for documenting concentrations of edge damage on an assemblage level to infer taphonomic processes and to record usewear and retouch. This approach is specifically aimed at patterning on the assemblage scale, rather than on individual artifacts. We use points from a Middle Stone Age assemblage from Pinnacle Point Cave 13B, near Mossel Bay, South Africa, to illustrate the technique. Combining GIS, rose diagrams, and polar statistics, we were able to visually and statistically summarize lithic artifacts for patterns of edge damage. For the points made on quartzite in this assemblage, edge damage was found to be significantly patterned and taphonomic causes of the damage were rejected. The technique also opens avenues for many other quantitative analyses that are either impossible or difficult with current non-visual systems of recording, such as measurements of distance, angle, and area of edge damage.     

Gazelle bone marrow yields and Epipalaeolithic carcass exploitation strategies in the southern Levant

We measure the bone marrow yields of mountain gazelle (Gazella gazella) carcasses to reconstruct gazelle exploitation strategies during the Epipalaeolithic periods in the southern Levant. We present experimentally derived data on the bone marrow content of seven fresh gazelle carcasses, determine the range of marrow yields among individuals of different sexes and seasons of death, and compare the new data to gazelle skeletal element abundances from five Epipalaeolithic assemblages from Israel. We found extensive variation in marrow fat content among individual gazelles. Animals with the highest marrow yields were killed in the spring while animals killed in the early autumn had lower fat contents. Nevertheless, our results suggest that gazelle marrow provided a reliable, albeit small fat resource for prehistoric foragers in all seasons. Strong relationships between bone fragmentation and marrow content demonstrate that Epipalaeolithic people preferentially processed bones with high marrow yields.