Papers by Maria Gutierrez
Paso Otero archaeological locality (Pampean region, Argentina) has provided detailed paleoenviron... more Paso Otero archaeological locality (Pampean region, Argentina) has provided detailed paleoenvironmental reconstructions and faunal assemblages from the Pleistocene/Holocene transition and Early
Holocene. This time span is represented by Paso Otero 5 (c. 10 450e10 200 14C BP; 12 593e11 353 cal. BP) and Paso Otero 4 (c. 9900e7700 14C BP; 10 667e7982 cal. BP). Palaeoenvironmental studies have been
carried out on the basis of data derived from geoarchaeological, sedimentary, palynofacies, pollen, diatoms and silica microremains. Unlike other areas of the Pampean region, bone assemblages from Paso
Otero include high representation and diversity of taxa. In this paper, paleoenvironmental reconstructions and faunal assemblages from both sites are integrated in order to discuss the consistency of the
inferences derived from the two lines of evidence, its contribution to the paleoecological scenarios, and to faunal extinctions. It is suggested that not only hunting pressure but the mere presence of humans was
a factor in ecosystem disturbance and is the most parsimonious explanation for the process of extinction.
This paper presents the results of a taphonomic research programme conducted over the past 5years... more This paper presents the results of a taphonomic research programme conducted over the past 5years. The main objective of the programme is to investigate differential survivorship in guanaco (Lama guanicoe) bones, taking into account the ontogenetic development of this species and the densitometric characteristics of its skeletal parts. First, density analysis was carried out on selected bones of modern individuals corresponding
to different age classes. Second, two experimental designs were conducted to explore the response of animal bone of different ages to weathering and fluvial transport. The first is a long term experiment that examines the deterioration of skeletal elements from a newborn, a juvenile and an adult modern guanaco exposed to subaerial weathering under controlled conditions. The second experiment examines the hydrodynamic sorting of dry and wet skeletal elements from a newborn, a juvenile, and an adult modern guanaco in an artificial flume under controlled current velocities (15 and 30cm/s). The main results of the research programme indicate that immature bones have higher hydric transport potential and weather at a
faster rate. We propose that this differential bone behaviour is partially related to structural density, as demonstrated by density analysis. These results show age-related biases in zooarchaeological assemblages
affected by taphonomic processes.
Subfossil muskrat remains are numerous in the lower strata at the Lubbock Lake Landmark, Southern... more Subfossil muskrat remains are numerous in the lower strata at the Lubbock Lake Landmark, Southern High Plains of Texas, dating from c. 11,100 BP to 8500 BP. This period witnessed a significant change in palaeoclimate and habitat at Lubbock Lake and the Southern High Plains. These changes caused the disappearance of many plant and animal species, and the emergence of many others. The muskrat, primarily herbivorous, altered their diet to accommodate these new plants. The scanning electron microscope and qualitative methods were used to analyse differences in dental
microwear patterns for the two Lubbock Lake populations most distant temporally. Differential microwear patterns on the enamel of the lower first molars consistent with the changes in vegetation known for Lubbock Lake during the period of muskrat habitation were found.
El registro arqueológico de la región pampeana (Argentina) indica la supervivencia de mamíferos d... more El registro arqueológico de la región pampeana (Argentina) indica la supervivencia de mamíferos de gran tamaño hasta ca. 7500 años AP, actualmente representados exclusivamente por xenartros. En las últimas décadas, análisis específicos sobre xenartros fósiles han permitido formular hipótesis paleobiológicas que podrían ayudar a comprender esta situación. Los estudios del aparato masticatorio, incluyendo área de la superficie oclusal dentaria, hipsodoncia y ancho relativo del hocico, han provisto hipótesis sobre dietas, hábitos alimenticios y preferencias de hábitat. Los resultados de estas líneas de investigación permiten proponer que los xenartros, en especial gliptodontes y perezosos terrestres, habrían consumido y explotado una gran variedad de recursos vegetales y hábitats y, por lo tanto, la coexistencia de varias especies herbívoras de xenartros pudo sustentarse a través del consumo diferencial de un amplio rango de recursos alimenticios. El objetivo de este trabajo es evaluar cómo los aspectos biológicos inferidos para estas especies pudieron haber representado ventajas en ambientes recientemente modificados, como aquellos de la transición Pleistoceno-Holoceno, en comparación con otros taxones (e.g., Artiodactyla, Perissodactyla), conduciendo, entre otras cosas, a la supervivencia diferencial de especies. Se presenta para ello información arqueológica, contextual, cronológica, así como los resultados derivados de los análisis paleobiológicos de estas especies.
Figura 2. Excavación del sitio La Moderna durante la década del '70, a cargo del Lic. Floreal Pal... more Figura 2. Excavación del sitio La Moderna durante la década del '70, a cargo del Lic. Floreal Palanca. Figura 1. Ubicación de los sitios arqueológicos La Moderna y Campo Laborde.
Faunal analysis, with a strong interdisciplinary emphasis, has played a key role in Pampean archa... more Faunal analysis, with a strong interdisciplinary emphasis, has played a key role in Pampean archaeology since the advent of the ecologic-systemic paradigm in the 1980s. From this point on, the archaeology of the region has made remarkable advances due to the increase in the number of sites investigated and the consequent generation of data that has contributed to fill preexisting spatial and chronological gaps. The present archaeofaunal record of the Pampean region has a broader temporal and spatial distribution. This situation encourages a new integration of the data and the building and/or rebuilding of former models of faunal exploitation.
The goal of this paper is to discuss the present state of the most outstanding aspects of the archaeozoological studies in the Pampean region. The time frame involved is the late Pleistocene to Holocene and the main issues discussed consist of a summary of archaeozoological evidences obtained from the region (sites, location, chronology, present and exploited species, etc.) and of the major faunal exploitation patterns, both on a regional and areal scale, throughout the studied period. The topics included in order to characterize this process are the climatic changes that operated on and influenced the species, differential species extinction and survival, exploited species diversity according to each studied period, procurement and processing techniques, and intensity of faunal exploitation, etc.
The evidence gathered and discussed for the purpose of this paper enable the characterization of the subsistence patterns of the region into at least three types. The late Pleistocene-early Holocene period (12,000-6500 BP) is characterized by a generalized regional economy. In general terms, a broad spectrum of resources would have been exploited by humans as suggested by the presence and diversity of consummed species during this time period. Given the fluctuating climatic conditions registered (climatic improvement-return to arid conditions-hypsythermal), a subsistence patttern composed of a broad diet would have been a suitable strategy to promote in risky environments. Both taxonomic diversity and richness are greater when compared with the following time period (middle Holocene).
The faunal richness recorded from four areas of the region within the middle Holocene (6500-3500 BP) is similar to that from the previous period. However, only a few species showed evidence of exploitation. This situation would be the result of specialized regional economies, with emphasis on guanaco (Lama guanicoe). The gap in the archaeological record at about 6000-5000 BP makes it harder to understand this process of change, and it is possible that this type of economy belonged to a more stable environment that may have established itself during the arid climatic trends after the Hypsythermal (8000-6000 BP), around 5000-4500 BP.
Finally, the archaeological record of almost all the areas of the region from the late Holocene (3500-500 BP) show an important taxonomic diversity and richness, each with its intrinsic peculiarities, that suggests the existence of areal economies of diversification and intensification of resource exploitation. These economies may have undergone changes towards 1000 BP as a consequence of the establishment of modern ecosystems and the hispanic-indigenous contact. Other non-faunal archaeological evidence from the late Holocene, such as an occupational redundancy of some sectors of the region, the introduction of new technologies (e.g. pottery, the bow and arrow, etc.), the intense use of preexisting technologies (grinding artefacts), long distance procurement of lithic raw material, the presence of exotic and ornamental elements, among others, suggest the existence of a pattern of intensification of these hunter-gatherer societies. These different strategies provide the pampean region as a whole with an important level of variability which should be understood in both ecologic terms and as the result of a complex social network of socio-cultural differentiation between areas that, however, would maintain strong bonds of socio-economic interdependency.
La meteorización ha sido una variable ampliamente utilizada en los análisis zooarqueológicos y ta... more La meteorización ha sido una variable ampliamente utilizada en los análisis zooarqueológicos y tafonómicos. Esta permite determinar si los restos óseos
estuvieron expuestos luego de su descarte por largos o cortos periodos de tiempo y evaluar la integridad del registro arqueofaunístico. El objetivo de este trabajo es identificar el modo en que la meteorización afecta a los distintos huesos del esqueleto de guanaco. Se evalúa si existe variabilidad en este proceso entre distintas unidades anatómicas y rangos etarios. Con
este fin se planteó una experiencia tafonómica en la cual se utilizaron huesos descarnados y hervidos de un individuo cría, juvenil y adulto. Los resultados obtenidos luego de dos años de exposición indican que en este corto período se registraron una variedad de cambios en los huesos (i.e., separación de partes de los elementos no fusionados, presencia de grietas,
líneas de desecación, exfoliación, pérdida de tejido óseo y fragmentación de los dientes) y una marcada diferencia en el grado de modificación de los huesos de un mismo esqueleto y entre esqueletos.
The Paso Otero Locality is a cluster of archaeological sites within the middle Rio Quequen Grande... more The Paso Otero Locality is a cluster of archaeological sites within the middle Rio Quequen Grande basin located in the northern coastal plain of Argentina. The valley fill is Holocene alluvial, eolian, and palustrine sediment, including the top of the Guerrero Member (∼10,000 14C yr B.P.), upper Rio Salado
Member (∼3000 14C yr B.P.), and lower La Postrera Formation (∼2400 14C yr B.P.). Regional soils include the Puesto Callejon Viejo (10,000 to 9400 14C yr B.P.) and the Puesto Berrondo (∼4800 14C yr B.P.). Radiocarbon sampling of buried A-horizons on both sides of the river produced 17 dates considered reliable. The geoarchaeological information allows exploration of the implications for the formation of the archaeological record. Similar geological processes of
differential intensity have resulted in contexts of different archaeological resolution and integrity. The Paso Otero Locality provides both a local and regional view of late Quaternary events and processes for the middle basin of the Rio Quequen Grande.
La Olla 1, in the Pampas of Argentina, is an open-air site located on the Atlantic coast in the M... more La Olla 1, in the Pampas of Argentina, is an open-air site located on the Atlantic coast in the Monte Hermoso District, southern Buenos Aires Province. Bones in lacustrine layers outcrop during very low tide exposed by longshore drift. Based on an initial analysis of the faunal assemblage, two species of sea mammal, guanaco, pampean deer, greater rhea, and a fish were represented in the almost 300 bones recovered during the rescue excavation. The lithic assemblage consisted of unifacially flaked tools, rounded cobbles reduced by bipolar technique, flakes, and artifacts with flat
abraded surfaces. Radiocarbon determinations of c. 7300 and 6600 came from sea mammal femora. An informal bone tool recovered from the site is made from the left proximal tibia of an adult otariid. It is identified as a utilitarian bone tool on the basis of use-wear characters that are restricted in distribution, and as a fracture-based bone tool on the basis of technological characters. The element was dynamically impacted in the mid-diaphysis region. Use-wear characters are loss of edge angularity, microflaking, pitting, striae, and polish. Microflaking occurs along the posterior fracture surface and exterior adjacent cortical surface. Pitting of the fracture surface extends along the entire length of the worn edge, but is most concentrated along the posterior fracture surface. A multitude of very fine striae runs parallel
to the fracture edge. The area of striations is limited to this edge with a well-demarcated boundary. Covering all of these characters is differential wear-polish. This high gloss polish is strongly reflective and occurs over very worn and rounded areas, providing a very bright, melted appearance. Based on these different use-wear patterns, the La Olla 1 bone tool
is interpreted as a dual-purpose implement most likely used for carcass dismemberment and hide processing. The La Olla 1 tool is unusual in that it is made from pinniped bone. Biomechanical analysis of southern fur seal bone
indicates, however, a strong suitability for impact-related tasks and, therefore, an appropriate choice for use as butchering tools.
Paso Otero 5 (Pampean region, Argentina) is characterized by the presence of extinct megamammals ... more Paso Otero 5 (Pampean region, Argentina) is characterized by the presence of extinct megamammals and modern species in association with fish-tail projectile points chronologically located ca. 10,450-10,200 yrs BP. The purpose of this paper is to summarize and discuss the results from several lines of evidence carried out for the last 10 years, particularly archaeological, chronological, geological, and paleonvironmental studies for the Pleistocene-Holocene transition. These results, integrated to regional information from other early sites, enable to highlight the main contributions of Paso Otero 5 to understanding hunter-gatherers adaptation and ways of life. In this sense, results indicate that a) human colonization occurred under cold, arid-semiarid, severe, and fluctuating climatic conditions; b) a great diversity of extinct species were recorded in a critical transitional period; c) megamammal bones were used as fuel; d) a planned and complex lithic technological strategy was developed; e) a good knowledge of the landscape and of resources distribution was acquired; f) wide home ranges and social interaction networks, both at a regional and extra-regional scale, were established by the Pleistocene-Holocene transition.
Durante el análisis de los restos óseos de guanaco, diferentes marcos de referencia son aplicados... more Durante el análisis de los restos óseos de guanaco, diferentes marcos de referencia son aplicados con el fin de evaluar cómo los distintos procesos tafonómicos han influido en la configuración de los conjuntos faunísticos estudiados. Estas herramientas han sido elaboradas a partir de muestras que comprenden uno o pocos individuos, lo cual tiende a encubrir la variabilidad de las propiedades medidas. Considerando esto, se está desarrollando una investigación que tiene como objetivo evaluar la densidad mineral ósea en huesos de guanaco de distinto desarrollo ontogénico. Con este fin se realizó una serie de experiencias tafonómicas sobre una muestra actual de guanacos compuesta por 54 individuos de diferentes edades, desde nonatos hasta seniles. Los resultados alcanzados indican la presencia de una variabilidad significativa en la muestra, vinculada a las propiedades de densidad mineral, fusión y estructura ósea, entre diferentes individuos y elementos óseos. En líneas generales, los huesos de los crías y juveniles tienen propiedades diferentes a las de los adultos, haciendo que su comportamiento ante distintos procesos tafonómicos sea diferencial. Este hecho cuestiona la aplicación que tradicionalmente ha sido dada a los marcos de referencia y abre la discusión acerca de su utilización en los análisis arqueofaunísticos.
The aim of this paper is to present and discuss the methodological criteria that may be useful to... more The aim of this paper is to present and discuss the methodological criteria that may be useful to explore the role water has in the formation of the faunal record in fluvial and lacustrine environments. In this sense, the dispersion potential of the bones that constitute an adult and neonate guanaco (Lama guanicoe) skeletons in an aqueous means with very low hydraulic energy, is evaluated through an experimentation. The results that derive from it are integrated with other complementary criteria and applied to the bone assemblage recovered at Paso Otero1 site, placed on the ancient flood plain margin of the Quequén Grande River (Buenos Aires Province, Argentina). The results of this study indicate that water was the main responsible agent for the guanaco bone accumulation in the site. It is proposed that some of the skeletal parts, which belong to guanaco carcasses that were processed and exploited by hunter-gatherers in areas close to the site, must have been added to those from the rest of the animals that died naturally. This resulted in a mixture of material both of natural and anthropic origin.
Samples of guanaco bone from an archaeological site in the Pampas of Argentina have been analysed... more Samples of guanaco bone from an archaeological site in the Pampas of Argentina have been analysed to understand the diagenetic profile of the bone assemblages that characterized the taphonomic history of the site. Two archaeological occupations of Paso Otero 1 were investigated, encompassing similar landscape settings, climates, and depositional environments. The time span is a c. 2000 year period from c. 4800 to 2800 years . A total of 30 bone samples taken from both occupations were used to provide a preliminary characterization of the diagenetic pathways at the site. The parameters investigated provide a comprehensive account of how both mineral (hydroxyapatite) and bone protein (collagen) have been altered. In order to compare the two bone assemblages in terms of their diagenetic parameters,
multivariate analyses were conducted. Results indicate two different diagenetic profiles in the site, % N being one of the
variables that accounts for most of the variation in Paso Otero 1. The diagenetic analyses indicate that protein is less preserved in the bone assemblage from the middle stable landscape. Alternative interpretations of the diagenetic profiles are discussed in light of the taphonomic history of the site, and palaeoenvironmental information of the region. One hypothesis stresses the importance of the role of climate in defining the different diagenetic pathways, and the other the continued action of the combined diagenetic factors along time as the main explanation for the variability in the state of preservation of the bones in Paso Otero 1.
Hydrodynamic sorting is a taphonomic process able to transport and scatter bones deposited in arc... more Hydrodynamic sorting is a taphonomic process able to transport and scatter bones deposited in archaeological and paleontological sites. This study presents the results of experimentation performed in an artificial flume with guanaco (Lama guanicoe) bones of different ontogenetic development, dry and saturated in water, in hydric flows velocities of 15 and 30 cm/s. The obtained results show that bone global density, the age of the individual, the dry or wet bone state, and the hydric flow velocity influence
significantly bone dispersion. In this way, bones from immature individuals with unfused secondary growth centers and relatively low bulk density have better possibility of being transported than fused bones from adult individuals. Taking into account the results obtained in this experimentation and the feasibility of discriminating age categories in fossil assemblages, two bone groups with differential potential transport are presented in this paper. These transport groups constitute a methodological tool to evaluate the role hydric current may had played in the formation of a fossil assemblage.
The aim of this paper is to present new information about bone mineral density (BMD) variability ... more The aim of this paper is to present new information about bone mineral density (BMD) variability in guanaco (Lama guanicoe), a South American wild camelid; while taking into account its ontogenic development. The importance of considering intrataxonomic variability in bone density related to age for
constructing zooarchaeological indices and applying them to archaeological assemblages is also discussed. The results presented here were developed from a large sample of 46 metacarpals and 45 femurs of modern guanacos, ranging in age from ca. 6 months of gestation to 12 years. Bone structural densities were measured using a biphotonic X-ray densitometer, DEXA method, Norland EXCELL and the bone mineral content (BMC) of each scanned portion or complete element was divided by its volume, which was obtained independently by water displacement. Our results indicate that the bone density of each
anatomical unit is highly variable, even among individuals of the same species. According to metacarpals data, age is an important factor affecting BMD. Moreover, our study shows that the density ranges of different skeletal elements can overlap, suggesting that it is not possible to predict that a certain element
is always denser than another one. Finally, we present new evidence about the potential age-related taphonomic bias in faunal assemblages, indicating that meanwhile some skeletal elements show clear differences in their density between their fused and unfused state (metacarpal) other do not (femur).
Taphonomy: Tyranny or Multivocality
This paper summarizes the development of taphonomic research ... more Taphonomy: Tyranny or Multivocality
This paper summarizes the development of taphonomic research conducted in the Interserrana Bonaerense area over the last fifteen years. In general,the different lines of research explored up to the present can be grouped into two main areas, the results of which are reviewed in this paper: 1) studies of faunal material recovered from archaeological sites (i.e., analysis
of the taphonomic effects of the archaeological bone assemblages; development and application of methodologies related to the study of the taphonomic effects; and bone diagenesis); and 2) actualistic studies that involve the development of experimental designs (i.e., the differential transport of skeletal parts by water; bone mineral density analysis; systematic observations on bone weathering). It is demonstrated throughout this paper that the integration of a taphonomic perspective into archaeological research enriches our interpretations of the human past. Moreover, the incorporation
of taphonomic observations and experiments enables significant
advances to be made in the knowledge of bone assemblage integrity and preservation through the generation of new data, the questioning of old ideas, the evaluation of assumptions, and the strengthening of archaeological interpretations.
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Papers by Maria Gutierrez
Holocene. This time span is represented by Paso Otero 5 (c. 10 450e10 200 14C BP; 12 593e11 353 cal. BP) and Paso Otero 4 (c. 9900e7700 14C BP; 10 667e7982 cal. BP). Palaeoenvironmental studies have been
carried out on the basis of data derived from geoarchaeological, sedimentary, palynofacies, pollen, diatoms and silica microremains. Unlike other areas of the Pampean region, bone assemblages from Paso
Otero include high representation and diversity of taxa. In this paper, paleoenvironmental reconstructions and faunal assemblages from both sites are integrated in order to discuss the consistency of the
inferences derived from the two lines of evidence, its contribution to the paleoecological scenarios, and to faunal extinctions. It is suggested that not only hunting pressure but the mere presence of humans was
a factor in ecosystem disturbance and is the most parsimonious explanation for the process of extinction.
to different age classes. Second, two experimental designs were conducted to explore the response of animal bone of different ages to weathering and fluvial transport. The first is a long term experiment that examines the deterioration of skeletal elements from a newborn, a juvenile and an adult modern guanaco exposed to subaerial weathering under controlled conditions. The second experiment examines the hydrodynamic sorting of dry and wet skeletal elements from a newborn, a juvenile, and an adult modern guanaco in an artificial flume under controlled current velocities (15 and 30cm/s). The main results of the research programme indicate that immature bones have higher hydric transport potential and weather at a
faster rate. We propose that this differential bone behaviour is partially related to structural density, as demonstrated by density analysis. These results show age-related biases in zooarchaeological assemblages
affected by taphonomic processes.
microwear patterns for the two Lubbock Lake populations most distant temporally. Differential microwear patterns on the enamel of the lower first molars consistent with the changes in vegetation known for Lubbock Lake during the period of muskrat habitation were found.
The goal of this paper is to discuss the present state of the most outstanding aspects of the archaeozoological studies in the Pampean region. The time frame involved is the late Pleistocene to Holocene and the main issues discussed consist of a summary of archaeozoological evidences obtained from the region (sites, location, chronology, present and exploited species, etc.) and of the major faunal exploitation patterns, both on a regional and areal scale, throughout the studied period. The topics included in order to characterize this process are the climatic changes that operated on and influenced the species, differential species extinction and survival, exploited species diversity according to each studied period, procurement and processing techniques, and intensity of faunal exploitation, etc.
The evidence gathered and discussed for the purpose of this paper enable the characterization of the subsistence patterns of the region into at least three types. The late Pleistocene-early Holocene period (12,000-6500 BP) is characterized by a generalized regional economy. In general terms, a broad spectrum of resources would have been exploited by humans as suggested by the presence and diversity of consummed species during this time period. Given the fluctuating climatic conditions registered (climatic improvement-return to arid conditions-hypsythermal), a subsistence patttern composed of a broad diet would have been a suitable strategy to promote in risky environments. Both taxonomic diversity and richness are greater when compared with the following time period (middle Holocene).
The faunal richness recorded from four areas of the region within the middle Holocene (6500-3500 BP) is similar to that from the previous period. However, only a few species showed evidence of exploitation. This situation would be the result of specialized regional economies, with emphasis on guanaco (Lama guanicoe). The gap in the archaeological record at about 6000-5000 BP makes it harder to understand this process of change, and it is possible that this type of economy belonged to a more stable environment that may have established itself during the arid climatic trends after the Hypsythermal (8000-6000 BP), around 5000-4500 BP.
Finally, the archaeological record of almost all the areas of the region from the late Holocene (3500-500 BP) show an important taxonomic diversity and richness, each with its intrinsic peculiarities, that suggests the existence of areal economies of diversification and intensification of resource exploitation. These economies may have undergone changes towards 1000 BP as a consequence of the establishment of modern ecosystems and the hispanic-indigenous contact. Other non-faunal archaeological evidence from the late Holocene, such as an occupational redundancy of some sectors of the region, the introduction of new technologies (e.g. pottery, the bow and arrow, etc.), the intense use of preexisting technologies (grinding artefacts), long distance procurement of lithic raw material, the presence of exotic and ornamental elements, among others, suggest the existence of a pattern of intensification of these hunter-gatherer societies. These different strategies provide the pampean region as a whole with an important level of variability which should be understood in both ecologic terms and as the result of a complex social network of socio-cultural differentiation between areas that, however, would maintain strong bonds of socio-economic interdependency.
estuvieron expuestos luego de su descarte por largos o cortos periodos de tiempo y evaluar la integridad del registro arqueofaunístico. El objetivo de este trabajo es identificar el modo en que la meteorización afecta a los distintos huesos del esqueleto de guanaco. Se evalúa si existe variabilidad en este proceso entre distintas unidades anatómicas y rangos etarios. Con
este fin se planteó una experiencia tafonómica en la cual se utilizaron huesos descarnados y hervidos de un individuo cría, juvenil y adulto. Los resultados obtenidos luego de dos años de exposición indican que en este corto período se registraron una variedad de cambios en los huesos (i.e., separación de partes de los elementos no fusionados, presencia de grietas,
líneas de desecación, exfoliación, pérdida de tejido óseo y fragmentación de los dientes) y una marcada diferencia en el grado de modificación de los huesos de un mismo esqueleto y entre esqueletos.
Member (∼3000 14C yr B.P.), and lower La Postrera Formation (∼2400 14C yr B.P.). Regional soils include the Puesto Callejon Viejo (10,000 to 9400 14C yr B.P.) and the Puesto Berrondo (∼4800 14C yr B.P.). Radiocarbon sampling of buried A-horizons on both sides of the river produced 17 dates considered reliable. The geoarchaeological information allows exploration of the implications for the formation of the archaeological record. Similar geological processes of
differential intensity have resulted in contexts of different archaeological resolution and integrity. The Paso Otero Locality provides both a local and regional view of late Quaternary events and processes for the middle basin of the Rio Quequen Grande.
abraded surfaces. Radiocarbon determinations of c. 7300 and 6600 came from sea mammal femora. An informal bone tool recovered from the site is made from the left proximal tibia of an adult otariid. It is identified as a utilitarian bone tool on the basis of use-wear characters that are restricted in distribution, and as a fracture-based bone tool on the basis of technological characters. The element was dynamically impacted in the mid-diaphysis region. Use-wear characters are loss of edge angularity, microflaking, pitting, striae, and polish. Microflaking occurs along the posterior fracture surface and exterior adjacent cortical surface. Pitting of the fracture surface extends along the entire length of the worn edge, but is most concentrated along the posterior fracture surface. A multitude of very fine striae runs parallel
to the fracture edge. The area of striations is limited to this edge with a well-demarcated boundary. Covering all of these characters is differential wear-polish. This high gloss polish is strongly reflective and occurs over very worn and rounded areas, providing a very bright, melted appearance. Based on these different use-wear patterns, the La Olla 1 bone tool
is interpreted as a dual-purpose implement most likely used for carcass dismemberment and hide processing. The La Olla 1 tool is unusual in that it is made from pinniped bone. Biomechanical analysis of southern fur seal bone
indicates, however, a strong suitability for impact-related tasks and, therefore, an appropriate choice for use as butchering tools.
multivariate analyses were conducted. Results indicate two different diagenetic profiles in the site, % N being one of the
variables that accounts for most of the variation in Paso Otero 1. The diagenetic analyses indicate that protein is less preserved in the bone assemblage from the middle stable landscape. Alternative interpretations of the diagenetic profiles are discussed in light of the taphonomic history of the site, and palaeoenvironmental information of the region. One hypothesis stresses the importance of the role of climate in defining the different diagenetic pathways, and the other the continued action of the combined diagenetic factors along time as the main explanation for the variability in the state of preservation of the bones in Paso Otero 1.
significantly bone dispersion. In this way, bones from immature individuals with unfused secondary growth centers and relatively low bulk density have better possibility of being transported than fused bones from adult individuals. Taking into account the results obtained in this experimentation and the feasibility of discriminating age categories in fossil assemblages, two bone groups with differential potential transport are presented in this paper. These transport groups constitute a methodological tool to evaluate the role hydric current may had played in the formation of a fossil assemblage.
constructing zooarchaeological indices and applying them to archaeological assemblages is also discussed. The results presented here were developed from a large sample of 46 metacarpals and 45 femurs of modern guanacos, ranging in age from ca. 6 months of gestation to 12 years. Bone structural densities were measured using a biphotonic X-ray densitometer, DEXA method, Norland EXCELL and the bone mineral content (BMC) of each scanned portion or complete element was divided by its volume, which was obtained independently by water displacement. Our results indicate that the bone density of each
anatomical unit is highly variable, even among individuals of the same species. According to metacarpals data, age is an important factor affecting BMD. Moreover, our study shows that the density ranges of different skeletal elements can overlap, suggesting that it is not possible to predict that a certain element
is always denser than another one. Finally, we present new evidence about the potential age-related taphonomic bias in faunal assemblages, indicating that meanwhile some skeletal elements show clear differences in their density between their fused and unfused state (metacarpal) other do not (femur).
This paper summarizes the development of taphonomic research conducted in the Interserrana Bonaerense area over the last fifteen years. In general,the different lines of research explored up to the present can be grouped into two main areas, the results of which are reviewed in this paper: 1) studies of faunal material recovered from archaeological sites (i.e., analysis
of the taphonomic effects of the archaeological bone assemblages; development and application of methodologies related to the study of the taphonomic effects; and bone diagenesis); and 2) actualistic studies that involve the development of experimental designs (i.e., the differential transport of skeletal parts by water; bone mineral density analysis; systematic observations on bone weathering). It is demonstrated throughout this paper that the integration of a taphonomic perspective into archaeological research enriches our interpretations of the human past. Moreover, the incorporation
of taphonomic observations and experiments enables significant
advances to be made in the knowledge of bone assemblage integrity and preservation through the generation of new data, the questioning of old ideas, the evaluation of assumptions, and the strengthening of archaeological interpretations.
Holocene. This time span is represented by Paso Otero 5 (c. 10 450e10 200 14C BP; 12 593e11 353 cal. BP) and Paso Otero 4 (c. 9900e7700 14C BP; 10 667e7982 cal. BP). Palaeoenvironmental studies have been
carried out on the basis of data derived from geoarchaeological, sedimentary, palynofacies, pollen, diatoms and silica microremains. Unlike other areas of the Pampean region, bone assemblages from Paso
Otero include high representation and diversity of taxa. In this paper, paleoenvironmental reconstructions and faunal assemblages from both sites are integrated in order to discuss the consistency of the
inferences derived from the two lines of evidence, its contribution to the paleoecological scenarios, and to faunal extinctions. It is suggested that not only hunting pressure but the mere presence of humans was
a factor in ecosystem disturbance and is the most parsimonious explanation for the process of extinction.
to different age classes. Second, two experimental designs were conducted to explore the response of animal bone of different ages to weathering and fluvial transport. The first is a long term experiment that examines the deterioration of skeletal elements from a newborn, a juvenile and an adult modern guanaco exposed to subaerial weathering under controlled conditions. The second experiment examines the hydrodynamic sorting of dry and wet skeletal elements from a newborn, a juvenile, and an adult modern guanaco in an artificial flume under controlled current velocities (15 and 30cm/s). The main results of the research programme indicate that immature bones have higher hydric transport potential and weather at a
faster rate. We propose that this differential bone behaviour is partially related to structural density, as demonstrated by density analysis. These results show age-related biases in zooarchaeological assemblages
affected by taphonomic processes.
microwear patterns for the two Lubbock Lake populations most distant temporally. Differential microwear patterns on the enamel of the lower first molars consistent with the changes in vegetation known for Lubbock Lake during the period of muskrat habitation were found.
The goal of this paper is to discuss the present state of the most outstanding aspects of the archaeozoological studies in the Pampean region. The time frame involved is the late Pleistocene to Holocene and the main issues discussed consist of a summary of archaeozoological evidences obtained from the region (sites, location, chronology, present and exploited species, etc.) and of the major faunal exploitation patterns, both on a regional and areal scale, throughout the studied period. The topics included in order to characterize this process are the climatic changes that operated on and influenced the species, differential species extinction and survival, exploited species diversity according to each studied period, procurement and processing techniques, and intensity of faunal exploitation, etc.
The evidence gathered and discussed for the purpose of this paper enable the characterization of the subsistence patterns of the region into at least three types. The late Pleistocene-early Holocene period (12,000-6500 BP) is characterized by a generalized regional economy. In general terms, a broad spectrum of resources would have been exploited by humans as suggested by the presence and diversity of consummed species during this time period. Given the fluctuating climatic conditions registered (climatic improvement-return to arid conditions-hypsythermal), a subsistence patttern composed of a broad diet would have been a suitable strategy to promote in risky environments. Both taxonomic diversity and richness are greater when compared with the following time period (middle Holocene).
The faunal richness recorded from four areas of the region within the middle Holocene (6500-3500 BP) is similar to that from the previous period. However, only a few species showed evidence of exploitation. This situation would be the result of specialized regional economies, with emphasis on guanaco (Lama guanicoe). The gap in the archaeological record at about 6000-5000 BP makes it harder to understand this process of change, and it is possible that this type of economy belonged to a more stable environment that may have established itself during the arid climatic trends after the Hypsythermal (8000-6000 BP), around 5000-4500 BP.
Finally, the archaeological record of almost all the areas of the region from the late Holocene (3500-500 BP) show an important taxonomic diversity and richness, each with its intrinsic peculiarities, that suggests the existence of areal economies of diversification and intensification of resource exploitation. These economies may have undergone changes towards 1000 BP as a consequence of the establishment of modern ecosystems and the hispanic-indigenous contact. Other non-faunal archaeological evidence from the late Holocene, such as an occupational redundancy of some sectors of the region, the introduction of new technologies (e.g. pottery, the bow and arrow, etc.), the intense use of preexisting technologies (grinding artefacts), long distance procurement of lithic raw material, the presence of exotic and ornamental elements, among others, suggest the existence of a pattern of intensification of these hunter-gatherer societies. These different strategies provide the pampean region as a whole with an important level of variability which should be understood in both ecologic terms and as the result of a complex social network of socio-cultural differentiation between areas that, however, would maintain strong bonds of socio-economic interdependency.
estuvieron expuestos luego de su descarte por largos o cortos periodos de tiempo y evaluar la integridad del registro arqueofaunístico. El objetivo de este trabajo es identificar el modo en que la meteorización afecta a los distintos huesos del esqueleto de guanaco. Se evalúa si existe variabilidad en este proceso entre distintas unidades anatómicas y rangos etarios. Con
este fin se planteó una experiencia tafonómica en la cual se utilizaron huesos descarnados y hervidos de un individuo cría, juvenil y adulto. Los resultados obtenidos luego de dos años de exposición indican que en este corto período se registraron una variedad de cambios en los huesos (i.e., separación de partes de los elementos no fusionados, presencia de grietas,
líneas de desecación, exfoliación, pérdida de tejido óseo y fragmentación de los dientes) y una marcada diferencia en el grado de modificación de los huesos de un mismo esqueleto y entre esqueletos.
Member (∼3000 14C yr B.P.), and lower La Postrera Formation (∼2400 14C yr B.P.). Regional soils include the Puesto Callejon Viejo (10,000 to 9400 14C yr B.P.) and the Puesto Berrondo (∼4800 14C yr B.P.). Radiocarbon sampling of buried A-horizons on both sides of the river produced 17 dates considered reliable. The geoarchaeological information allows exploration of the implications for the formation of the archaeological record. Similar geological processes of
differential intensity have resulted in contexts of different archaeological resolution and integrity. The Paso Otero Locality provides both a local and regional view of late Quaternary events and processes for the middle basin of the Rio Quequen Grande.
abraded surfaces. Radiocarbon determinations of c. 7300 and 6600 came from sea mammal femora. An informal bone tool recovered from the site is made from the left proximal tibia of an adult otariid. It is identified as a utilitarian bone tool on the basis of use-wear characters that are restricted in distribution, and as a fracture-based bone tool on the basis of technological characters. The element was dynamically impacted in the mid-diaphysis region. Use-wear characters are loss of edge angularity, microflaking, pitting, striae, and polish. Microflaking occurs along the posterior fracture surface and exterior adjacent cortical surface. Pitting of the fracture surface extends along the entire length of the worn edge, but is most concentrated along the posterior fracture surface. A multitude of very fine striae runs parallel
to the fracture edge. The area of striations is limited to this edge with a well-demarcated boundary. Covering all of these characters is differential wear-polish. This high gloss polish is strongly reflective and occurs over very worn and rounded areas, providing a very bright, melted appearance. Based on these different use-wear patterns, the La Olla 1 bone tool
is interpreted as a dual-purpose implement most likely used for carcass dismemberment and hide processing. The La Olla 1 tool is unusual in that it is made from pinniped bone. Biomechanical analysis of southern fur seal bone
indicates, however, a strong suitability for impact-related tasks and, therefore, an appropriate choice for use as butchering tools.
multivariate analyses were conducted. Results indicate two different diagenetic profiles in the site, % N being one of the
variables that accounts for most of the variation in Paso Otero 1. The diagenetic analyses indicate that protein is less preserved in the bone assemblage from the middle stable landscape. Alternative interpretations of the diagenetic profiles are discussed in light of the taphonomic history of the site, and palaeoenvironmental information of the region. One hypothesis stresses the importance of the role of climate in defining the different diagenetic pathways, and the other the continued action of the combined diagenetic factors along time as the main explanation for the variability in the state of preservation of the bones in Paso Otero 1.
significantly bone dispersion. In this way, bones from immature individuals with unfused secondary growth centers and relatively low bulk density have better possibility of being transported than fused bones from adult individuals. Taking into account the results obtained in this experimentation and the feasibility of discriminating age categories in fossil assemblages, two bone groups with differential potential transport are presented in this paper. These transport groups constitute a methodological tool to evaluate the role hydric current may had played in the formation of a fossil assemblage.
constructing zooarchaeological indices and applying them to archaeological assemblages is also discussed. The results presented here were developed from a large sample of 46 metacarpals and 45 femurs of modern guanacos, ranging in age from ca. 6 months of gestation to 12 years. Bone structural densities were measured using a biphotonic X-ray densitometer, DEXA method, Norland EXCELL and the bone mineral content (BMC) of each scanned portion or complete element was divided by its volume, which was obtained independently by water displacement. Our results indicate that the bone density of each
anatomical unit is highly variable, even among individuals of the same species. According to metacarpals data, age is an important factor affecting BMD. Moreover, our study shows that the density ranges of different skeletal elements can overlap, suggesting that it is not possible to predict that a certain element
is always denser than another one. Finally, we present new evidence about the potential age-related taphonomic bias in faunal assemblages, indicating that meanwhile some skeletal elements show clear differences in their density between their fused and unfused state (metacarpal) other do not (femur).
This paper summarizes the development of taphonomic research conducted in the Interserrana Bonaerense area over the last fifteen years. In general,the different lines of research explored up to the present can be grouped into two main areas, the results of which are reviewed in this paper: 1) studies of faunal material recovered from archaeological sites (i.e., analysis
of the taphonomic effects of the archaeological bone assemblages; development and application of methodologies related to the study of the taphonomic effects; and bone diagenesis); and 2) actualistic studies that involve the development of experimental designs (i.e., the differential transport of skeletal parts by water; bone mineral density analysis; systematic observations on bone weathering). It is demonstrated throughout this paper that the integration of a taphonomic perspective into archaeological research enriches our interpretations of the human past. Moreover, the incorporation
of taphonomic observations and experiments enables significant
advances to be made in the knowledge of bone assemblage integrity and preservation through the generation of new data, the questioning of old ideas, the evaluation of assumptions, and the strengthening of archaeological interpretations.