Phytolith taphonomy and distributions in archeological sediments from Panama

This paper presents the results of research into the nature, distribution and significance of phytoliths in archeological sediments from Panama. Four sites are investigated that span a time period dated by radiocarbon from 6600 BC to AD 500, and which encompass a range of human adaptations and ecological settings. The strengths and limitations of phytolith analysis are evaluated in relation to a diverse set of paleoecological issues. The results indicate that Panamanian archeological deposits contribute silicified structures from a large number of plant taxa. Phytoliths appear to be horizontally and vertically stable after deposition. There are problems in human paleoecology, such as the evolution of root cropping systems, that are not amenable to study with phytolith data. However, a considerable amount of information can be generated about some components of prehistoric seed cropping systems, wild plant usage, and landforms.     

Life tables in palaeodemography: A methodological note

Several errors in the early literature discussing life-table analysis of skeletal populations are potentially misleading to the researcher unacquainted with the mathematical methods of palaeodemography. Additional errors document the hazards of borrowing life-table methods and equations from other applications without fully realizing their context, interpretation, and the potential restrictions on their use. A simple generalization of the life-table equations explicitly to reveal their dependence on the entry age and width of the age intervals used will facilitate the correct computation of life tables and readily accommodate the use of unconventional or otherwise non-standard cohorts. A general procedure for computing a life table for a skeletal population is presented, and a numerical example is included to illustrate the method.     

Particle size distribution of lithic assemblages and taphonomy of Palaeolithic sites

Lithic debris derived from knapping and used tools can be assimilated to simple sedimentary particles that may undergo size sorting when exposed to geomorphic processes such as streamflow or overland flow. Sorting can be identified by comparing the size distribution of archaeological assemblages to that of experimental core reduction sequences. A new database including different types of raw material (mainly flint and quartzite) and Palaeolithic debitage (blade, Levallois, discoid, on anvil, and shaping) has been built for this purpose. Palaeoeskimo data have also been added to illustrate microlithic industries. For all the debitages and raw materials, the particle size of knapping products >2 mm in width fits with a power-law distribution and shows only minor fluctuations, the range of which is always <15% between experiments (all steps of the chaîne opératoire included up to the final tool). A lithic assemblage derived from block/core knapping or blank/preform production will display a particle size distribution close to the experimental distributions if not subsequently modified. Modifications may originate either from sedimentary processes or from anthropogenic factors. To help distinguishing amongst these, data on the impact of both water flows on sedimentary particles or experimental assemblages, and anthropogenic processes such as importation-exportation (of core, preforms or finished tools) or uneven spatial distribution of the different steps in core reduction and tool production within a site, are reviewed. By contrast to anthropogenic modifications, sedimentary processes are generally typified by strong impoverishment in or selective accumulation of fine-grained (<10 mm) artefacts together with a low intra-site variability (spatial homogenization) or a downslope size trend. Archaeological case studies taken from French Palaeolithic site are then detailed. Evidence for lithic redistribution implies that care should be taken in archaeological site analysis since sorting may impact significantly the initial techno-typological balance of the assemblage.     

The taphonomy and palaeoenvironmental implications of the small mammals from Karain Cave,Turkey

The small mammal accumulations in the Pleistocene deposits of Karain Cave are investigated to identify the predators and possible biases in the fossil assemblages. Seven small mammal assemblages are studied in chronological order from two chambers of the cave, the main chamber E and the side chamber B. The lowermost level within the whole sequence is Proto-Charentien, which corresponds to an early stage of the Middle Palaeolithic. The main part of the material belongs to Middle Palaeolithic layers. The most important aspect of the fossil record in the cave is the human occupation without any interruption through the Pleistocene to Holocene. The small mammal fossil evidence in the cave denotes the presence of opportunistic predators throughout the sequence with one exception, and these produce balanced samples of small mammal faunas in the habitat. The lack of bias in the small mammal faunas allow the interpretation of local environments, showing that partial steppe and arid conditions existed during deposition of the lowermost levels of the Middle Palaeolithic in Karain Cave and that these shifted into more temperate and wooded habitat in the upper levels. Evidence from the side chamber indicates some differences, with a more open grassy environment. In the Mediterranean part of Anatolia the temperate and moist conditions in the Middle Palaeolithic were superseded by more arid conditions in the Upper Palaeolithic, followed by a decrease in steppe conditions during the Epi-Palaeolithic period.     

Human taphonomy at Khuzhir-Nuge XIV,Siberia: a new method for documenting skeletal condition

This paper employs a new three-part method for documenting skeletal condition in order to examine human taphonomy at the Glaskovo (5000–3700 BP, calibrated) cemetery of Khuzhir-Nuge XIV, located in the Lake Baikal region of Siberia (Russia). Relationships among three distinct aspects of condition – completeness, fragmentation, and articulation – and 15 identified taphonomic factors are investigated in order to explain the high variability observed at the site. Intrinsic skeletal characteristics such as element type and age at death were found to be responsible for some of the variable condition, but cultural activities, particularly mortuary practices, appear to have played even greater roles – both direct and indirect. Articulation, in particular, appears to have been an aspect of skeletal condition which was directly affected by a number of cultural practices. In addition to applying a new method of documenting skeletal condition to human taphonomic analyses, this research explains much of the variable condition observed at Khuzhir-Nuge XIV and emphasizes the significance of cultural practices as taphonomic agents affecting human remains.     

Volume density of South American camelid skeletal parts

This paper provides a set of volume density values for skeletal parts of lama (Mammalia, Artiodactyla, Camelidae). The method by which these values were obtained is described and compared with published data of densitometries made on cervids, showing a high positive correlation between the bone densities of the two artiodactyls. The camelid bone density data are used to discuss the interpretation of skeletal patterning in an Andean archaeofaunal assemblage.     

Experimental effects of bone size and temperature on bone diagenesis

In the ground, bone undergoes chemical and physical changes which affect its preservation. This fact has important implications for dating and other analytical procedures involving bone, as well as faunal analysis where differential preservation of bones of different species may affect conclusions regarding the relative significance of an animal to the economy of a given society. The diagenic processes in bone range from minor changes in the bone protein to complete structural and chemical breakdown.Using fresh cow bone, we conducted laboratory experiments which simulate the effect of temperature and bone size on the rate and nature of bone disintegration in archaeological sites. Temperature influences the rate of chemical change, and bone size and density affect the accessibility of the molecular constituents of bone to extrinsic chemical reactions. These findings clarify the importance of two well-known concepts in bone taphonomy. (1) The rate of chemical breakdown in bone tissues is related to the proximity of a given unit of tissue to the bone surface. This means that, in archaeological bone samples, tissue near the surface may be different chemically from tissue away from the surface and great care is necessary in choosing and preparing bone samples for analytical procedures. (2) In general, small bones are not as well preserved as large bones, therefore small animals are likely to be underrepresented in faunal assemblages.     

Avian taphonomy: observations at two Magellanic penguin (Spheniscus magellanicus) breeding colonies and their implications for the fossil record

Actualistic studies on vertebrate taphonomy have centred on mammals, and to a much lesser extent on flying birds. Members of the Spheniscidae are anatomically specialized making it problematic to make direct inferences from previous taphonomic work. Modern bone assemblages from two Spheniscus magellanicus breeding colonies on the southern Atlantic coast of continental Patagonia, Argentina, were surveyed on foot along linear transects, and features were determined that are useful in interpreting the fossil record. Present day bone accumulations have specific properties resulting from penguin anatomy and osteology as well as from the composition of the vertebrate community and regional environmental conditions. Most salient are the high spatial density of bones, the dominance of Spheniscidae remains over those of other vertebrates, the high percentage of disarticulated bones, the predominance of limb bones, the low frequencies of carnivore bone modifications, and the abundance of fractured bones. Many of these features observed in the modern assemblages can be identified in fossil avian bone deposits.     

Bone surface modifications in zooarchaeology

Cutmarks made by stone tools, conchoidal flake scars from hammerstone percussion, carnivore tooth marks, striations from sedimentary abrasion, and other surface modifications on bones from archaeological sites constitute a crucial body of evidence for investigating the role of human behaviors and of nonhuman taphonomic processes in site formation. This paper describes the various kinds of bone surface modifications produced by humans and by nonhuman processes and assesses the current status of bone surface modification studies with regard to such issues as the need for greater analytical standardization, the selection of instruments for examining bone specimens, tactics for identifying the origins of marks on bones, and strategies for inferring human behaviors.     

The Spatial Organization of Bone Crafting During the Middle and Late Mesolithic at Ringsjöholm and Strandvägen in Sweden

This paper focuses on the spatial distribution of bone tool production waste from two Mesolithic sites in Sweden, Ringsjöholm and Strandvägen, with well-preserved faunal remains including bone and antler artifacts. Local production on both sites has generated a variety of identifiable waste products deriving from complete chains of production, including unmodified bones, debitage and finished products. Identified categories include: blanks, removed epiphyses, bone flakes, and preforms. Identification of species shows that antler and bone from red deer were the preferred raw materials. Spatial statistical analyses confirm that different stages of bone tool production were organized within separate areas of the sites and that larger items were discarded in the water along the shorelines. Interestingly, blanks and preforms seem to have been stored under water for future use and demarcated clusters of bone flakes in association with dwellings represent “bone knapping floors” where production was more intense than in other areas.     

Human digestive effects on a micromammalian skeleton

This study describes the results of an experiment involving the consumption of a skinned, eviscerated, and segmented insectivore by an adult human male. Bone remains from recovered faecal contents are examined for skeletal element representation, breakage and digestive damage. Detailed examination of each category suggests severe skeletal attrition which is comparable to, and at times in excess of, the damage exhibited in microvertebrate skeletal accumulations originating from the scats of small mammalian carnivores.     

Bone frequencies: differential transport, in situ destruction,and the MGUI

Human transport of bones with high food values, and destruction of bones with low density values are the traditionally invoked explanations of the frequencies of bones in archeological contexts. The manner in which these two explanations have been used suggests archaeologists assume the explanations to be independent of one another. The transport explanation is operationalized as the modified general utility index (MGUI) of Binford, and the destruction explanation is operationalized with measures of bone density. Statistical correlation of the MGUI with bone density, while weak, indicates that many high utility bones have low density values while many low utility bones have high density values. Because low density bones tend to be destroyed more readily than high density bones, inferences of human utility strategies derived from bone frequencies and based on the MGUI may be inaccurate. The utility strategies suggested by three archaeofaunas are compared to bone density, and two of these faunas are shown to potentially be the result of differential destruction and not human transport as measured by the MGUI.