The Lesser Rhea (Rhea pennata), a large flightless bird native to South America, held
historical ... more The Lesser Rhea (Rhea pennata), a large flightless bird native to South America, held historical significance as a vital resource for Patagonian hunter–gatherer societies. Despite the species' cultural and ecological importance, the historical population dynamics of R. pennata remain poorly understood. Although present in the archaeological record, its abundance is not consistently documented and the reasons remain unclear. This study investigates the late Holocene population trends of R. pennata using ancient DNA analysis. By analyzing complete mitochondrial genome sequences from dated archaeological specimens, we reveal a significant population increase from 700 to 500 years Before Present (BP), followed by a period of relative stability from 500 to 300 years BP. Subsequently, a subtle decline in population size is observed, coinciding with the arrival of European settlers; however, due to considerable uncertainty in population estimates, definitive conclusions regarding this decline are challenging to make. Historical records indicate heightened rhea hunting during this period, coterminous with a decrease in the abundance of rhea eggshell fragments. It is suggested that climatic factors may have influenced these population dynamics, particularly favoring rhea population growth from 700 to 500 years BP. This study contributes to our understanding of the historical ecology and humanrhea interactions in Patagonia, emphasizing the importance of interdisciplinary approaches in reconstructing past population dynamics.
The aim of this paper is to study the use of ceramics of small-scale societies during the late Ho... more The aim of this paper is to study the use of ceramics of small-scale societies during the late Holocene in northern Patagonia. The technological investment model predicts that use-time and utility will determine the investment spent in ceramics. We explore how ceramics were used in short-term camps and aggregation sites during summer at high elevations, and residential camps during winter at lower elevations. To test the investment in ceramics we use four technological variables: temper size, average thickness, surface treatment and firing. Our results indicate that hunter-gatherers expected a short-term use in summer locations and therefore made a low investment in ceramics.
This paper presents the results of a study on the isotopic ecology of guanacos in central western... more This paper presents the results of a study on the isotopic ecology of guanacos in central western Argentina. We examine the historical population ecology of guanacos using stable isotope analysis of bone collagen from pre-Hispanic and modern guanaco populations (n = 129), considering variability in two ecoregions: the Monte hot desert and the Andean-Patagonian cold desert. Our study addresses the consistency of guanaco diets over time, evaluating palaeoecology to provide information for conservation of this taxon. We found significant differences in isotopic niche size between modern and archaeological guanacos. When analyzed by ecoregion, there were significant differences in niche size through time, indicating that guanacos had distinctive dietary habits and occupied different ecological niches across the ecoregions. Comparing Standard Ellipse Areas (SEA) through time and across space, we observed that the archaeological SEA for guanacos is smaller than its modern counterpart in the Andean-Patagonia ecoregion. Conversely, in Monte, the archaeological SEA is larger than the one established for modern samples. The contrast between pre-Hispanic and modern populations highlight the impact of human activity and conservation efforts on the distribution and ecology of guanacos. These findings have important implications for understanding guanaco ecology with consequences for conservation policies.
En esta contribución se presenta el análisis zooarqueológico y arqueobotánico de los materiales h... more En esta contribución se presenta el análisis zooarqueológico y arqueobotánico de los materiales hallados en el Sitio Cueva Palulo, localizado en las márgenes de un arroyo tributario del río Atuel, en el sur de la provincia de Mendoza. Los materiales fueron analizados considerando problemáticas de índole regional, como el proceso de intensificación propuesto y discutido en diversos trabajos. Antes de realizar interpretaciones sobre el consumo de recursos se atendió a los procesos de formación del sitio y a cuestiones tafonómicas para evitar interpretaciones erróneas sobre el uso de las plantas y animales por parte de las poblaciones de cazadores recolectores que habitaron la región. Los resultados alcanzados señalan que en este sitio no se registran cambios como los que plantea el modelo de intensificación propuesto para la región ca. de los 2000 años AP. Si bien parece haber mayor intensidad en el aprovechamiento del guanaco, no se registra, un aumento en la diversidad de taxones ex...
En este trabajo presentamos los resultados de la prueba piloto del muestreo sistemático en la cue... more En este trabajo presentamos los resultados de la prueba piloto del muestreo sistemático en la cuenca distal del río Diamante, en su desembocadura en el sistema fluvial Desaguadero-Salado. Se analizan los distintos elementos del paisaje y su relación con la presencia de registro arqueológico. Se observan también las relaciones entre registro de precipitaciones y caudales del río para indagar acerca de la potencialidad de este indicador para predecir desbordes de río y su impacto en la preservación del registro arqueológico. Durante las prospecciones realizadas, hemos logrado detectar que el registro arqueológico se encuentra asociado de manera recurrente a sectores desmontados, elevados, en los que predominan sedimentos eólicos. En cuanto a los hallazgos arqueológicos recuperados en los sitios excavados, se observaron diferencias significativas en la distribución de los mismos a lo largo de la estratigrafía. A partir de los resultados obtenidos, proponemos un tipo de muestreo arqueológico de superficie diferente al utilizado en trabajos de campo previos.
This paper presents the results of a study on the isotopic ecology of guanacos in central western... more This paper presents the results of a study on the isotopic ecology of guanacos in central western Argentina. We examine the historical population ecology of guanacos using stable isotope analysis of bone collagen from pre-Hispanic and modern guanaco populations (n = 129), considering variability in two ecoregions: the Monte hot desert and the Andean-Patagonian cold desert. Our study addresses the consistency of guanaco diets over time, evaluating palaeoecology to provide information for conservation of this taxon. We found significant differences in isotopic niche size between modern and archaeological guanacos. When analyzed by ecoregion, there were significant differences in niche size through time, indicating that guanacos had distinctive dietary habits and occupied different ecological niches across the ecoregions. Comparing Standard Ellipse Areas (SEA) through time and across space, we observed that the archaeological SEA for guanacos is smaller than its modern counterpart in the Andean-Patagonia ecoregion. Conversely, in Monte, the archaeological SEA is larger than the one established for modern samples. The contrast between pre-Hispanic and modern populations highlight the impact of human activity and conservation efforts on the distribution and ecology of guanacos. These findings have important implications for understanding guanaco ecology with consequences for conservation policies.
rates on seed crops and animal products, like bone, if cooking releases more calories relative to... more rates on seed crops and animal products, like bone, if cooking releases more calories relative to the time invested in their acquisition (Bettinger et al. 2006; Sturm et al. 2016). In this paper, we explore the following research question: How was ceramic technology used by small-scale mobile societies in the highlands of northwestern Patagonia?
Tafonomía actualística longitudinal de endoesqueleto y exoesqueleto de Zaedyus pichiy y de cáscar... more Tafonomía actualística longitudinal de endoesqueleto y exoesqueleto de Zaedyus pichiy y de cáscaras de huevos de Rheidae en un contexto controlado
Pumas are American top predators that commonly frequent places that may also be inhabited by huma... more Pumas are American top predators that commonly frequent places that may also be inhabited by humans. With the aim of contributing to the evaluation of the accumulating processes and agents of vertebrate remains of archaeological and paleontological sites, we analyzed a modern puma scat-derived vertebrate bone assemblage from an area of the central Monte Desert, one of the most arid regions of South America. We evaluated the taphonomic signature of vertebrate remains recovered in such scats without discriminating among the different types of fauna, which strengthens this taphonomic contribution. Despite the high availability of domestic and exotic fauna from livestock fields in the surroundings of the area, the assemblage was dominated by typical native small and medium-sized fauna from xeric environments of the Monte biome. The armadillo Zaedyus pichiy was the most frequent taxon, followed by the caviid rodents Microcavia maenas and Galea leucoblephara, and the Tinamidae Eudromia elegans. The most remarkable taphonomic signatures are high breakage; a high proportion and degree of elements with evidence of digestion; and a low number of tooth marks. We find a good proportion of identifiable specimens, considering the previous assumptions on the extreme destruction of felid scat-derived vertebrate bone assemblages. A first assessment was made of specimens little known from a regional taphonomic perspective, such as armadillo osteoderms or bird remains. The taphonomic analysis of this multi-taxa accumulation enables a solid evaluation of vertebrate bone assemblages from archaeological and paleontological sites.
Many cultural and natural processes form the archaeological record. Taphonomy, the study of the t... more Many cultural and natural processes form the archaeological record. Taphonomy, the study of the transition of organic matter from living contexts (the biosphere) to geological contexts (the lithosphere), aids in understanding how agents and processes affect skeletal remains in the archaeological record. In this paper the results of an actualistic taphonomic study on deposition of bones in open-air and cave contexts in the high elevation Andes Mountains are presented. Results indicate that within the first three months after deposition many bones are displaced or removed from sites and that the agents that act in each context are different. Horizontal displacement of bones from their deposited locations is limited in the cave context but is dominant in the open air site. Carnivores appear to be responsible for moving bones in open-air contexts, and rodents appear to displace bones vertically in the cave context. Such naturalistic experiments are important in particular areas of the w...
En este trabajo se presentan los resultados del análisis de cuatro sitios arqueológicos localizad... more En este trabajo se presentan los resultados del análisis de cuatro sitios arqueológicos localizados en los valles cordilleranos de altitud intermedia del río Diamante: El Perdido 1, El Perdido 4, El Perdido 5 y HI95.Se utiliza la información de materiales arqueológicos recolectados en superficie y de sondeos estratigráficos realizados en cada uno de estos sitos. El objetivo del trabajo es caracterizar el tipo de asentamiento y evaluar si hubo un uso diferencial de este espacio. Se busca, a su vez, evaluar cambios a lo largo del tiempo y entre sitios analizados. En este sentido, se encontraron diferencias en la intensidad de uso de cada uno de estos sitios. El Perdido 1 se presenta como el sitio con mayor intensidad de uso y mayor diversidad artefactual, por el contrario, HI95 es el que posee menor intensidad de uso. Para evaluar las diferencias en la intensidad de uso de cada sitio se consideró la disponibilidad de materias primas líticas y la localización de las mismas. En cuanto a...
The Lesser Rhea (Rhea pennata), a large flightless bird native to South America, held
historical ... more The Lesser Rhea (Rhea pennata), a large flightless bird native to South America, held historical significance as a vital resource for Patagonian hunter–gatherer societies. Despite the species' cultural and ecological importance, the historical population dynamics of R. pennata remain poorly understood. Although present in the archaeological record, its abundance is not consistently documented and the reasons remain unclear. This study investigates the late Holocene population trends of R. pennata using ancient DNA analysis. By analyzing complete mitochondrial genome sequences from dated archaeological specimens, we reveal a significant population increase from 700 to 500 years Before Present (BP), followed by a period of relative stability from 500 to 300 years BP. Subsequently, a subtle decline in population size is observed, coinciding with the arrival of European settlers; however, due to considerable uncertainty in population estimates, definitive conclusions regarding this decline are challenging to make. Historical records indicate heightened rhea hunting during this period, coterminous with a decrease in the abundance of rhea eggshell fragments. It is suggested that climatic factors may have influenced these population dynamics, particularly favoring rhea population growth from 700 to 500 years BP. This study contributes to our understanding of the historical ecology and humanrhea interactions in Patagonia, emphasizing the importance of interdisciplinary approaches in reconstructing past population dynamics.
The aim of this paper is to study the use of ceramics of small-scale societies during the late Ho... more The aim of this paper is to study the use of ceramics of small-scale societies during the late Holocene in northern Patagonia. The technological investment model predicts that use-time and utility will determine the investment spent in ceramics. We explore how ceramics were used in short-term camps and aggregation sites during summer at high elevations, and residential camps during winter at lower elevations. To test the investment in ceramics we use four technological variables: temper size, average thickness, surface treatment and firing. Our results indicate that hunter-gatherers expected a short-term use in summer locations and therefore made a low investment in ceramics.
This paper presents the results of a study on the isotopic ecology of guanacos in central western... more This paper presents the results of a study on the isotopic ecology of guanacos in central western Argentina. We examine the historical population ecology of guanacos using stable isotope analysis of bone collagen from pre-Hispanic and modern guanaco populations (n = 129), considering variability in two ecoregions: the Monte hot desert and the Andean-Patagonian cold desert. Our study addresses the consistency of guanaco diets over time, evaluating palaeoecology to provide information for conservation of this taxon. We found significant differences in isotopic niche size between modern and archaeological guanacos. When analyzed by ecoregion, there were significant differences in niche size through time, indicating that guanacos had distinctive dietary habits and occupied different ecological niches across the ecoregions. Comparing Standard Ellipse Areas (SEA) through time and across space, we observed that the archaeological SEA for guanacos is smaller than its modern counterpart in the Andean-Patagonia ecoregion. Conversely, in Monte, the archaeological SEA is larger than the one established for modern samples. The contrast between pre-Hispanic and modern populations highlight the impact of human activity and conservation efforts on the distribution and ecology of guanacos. These findings have important implications for understanding guanaco ecology with consequences for conservation policies.
En esta contribución se presenta el análisis zooarqueológico y arqueobotánico de los materiales h... more En esta contribución se presenta el análisis zooarqueológico y arqueobotánico de los materiales hallados en el Sitio Cueva Palulo, localizado en las márgenes de un arroyo tributario del río Atuel, en el sur de la provincia de Mendoza. Los materiales fueron analizados considerando problemáticas de índole regional, como el proceso de intensificación propuesto y discutido en diversos trabajos. Antes de realizar interpretaciones sobre el consumo de recursos se atendió a los procesos de formación del sitio y a cuestiones tafonómicas para evitar interpretaciones erróneas sobre el uso de las plantas y animales por parte de las poblaciones de cazadores recolectores que habitaron la región. Los resultados alcanzados señalan que en este sitio no se registran cambios como los que plantea el modelo de intensificación propuesto para la región ca. de los 2000 años AP. Si bien parece haber mayor intensidad en el aprovechamiento del guanaco, no se registra, un aumento en la diversidad de taxones ex...
En este trabajo presentamos los resultados de la prueba piloto del muestreo sistemático en la cue... more En este trabajo presentamos los resultados de la prueba piloto del muestreo sistemático en la cuenca distal del río Diamante, en su desembocadura en el sistema fluvial Desaguadero-Salado. Se analizan los distintos elementos del paisaje y su relación con la presencia de registro arqueológico. Se observan también las relaciones entre registro de precipitaciones y caudales del río para indagar acerca de la potencialidad de este indicador para predecir desbordes de río y su impacto en la preservación del registro arqueológico. Durante las prospecciones realizadas, hemos logrado detectar que el registro arqueológico se encuentra asociado de manera recurrente a sectores desmontados, elevados, en los que predominan sedimentos eólicos. En cuanto a los hallazgos arqueológicos recuperados en los sitios excavados, se observaron diferencias significativas en la distribución de los mismos a lo largo de la estratigrafía. A partir de los resultados obtenidos, proponemos un tipo de muestreo arqueológico de superficie diferente al utilizado en trabajos de campo previos.
This paper presents the results of a study on the isotopic ecology of guanacos in central western... more This paper presents the results of a study on the isotopic ecology of guanacos in central western Argentina. We examine the historical population ecology of guanacos using stable isotope analysis of bone collagen from pre-Hispanic and modern guanaco populations (n = 129), considering variability in two ecoregions: the Monte hot desert and the Andean-Patagonian cold desert. Our study addresses the consistency of guanaco diets over time, evaluating palaeoecology to provide information for conservation of this taxon. We found significant differences in isotopic niche size between modern and archaeological guanacos. When analyzed by ecoregion, there were significant differences in niche size through time, indicating that guanacos had distinctive dietary habits and occupied different ecological niches across the ecoregions. Comparing Standard Ellipse Areas (SEA) through time and across space, we observed that the archaeological SEA for guanacos is smaller than its modern counterpart in the Andean-Patagonia ecoregion. Conversely, in Monte, the archaeological SEA is larger than the one established for modern samples. The contrast between pre-Hispanic and modern populations highlight the impact of human activity and conservation efforts on the distribution and ecology of guanacos. These findings have important implications for understanding guanaco ecology with consequences for conservation policies.
rates on seed crops and animal products, like bone, if cooking releases more calories relative to... more rates on seed crops and animal products, like bone, if cooking releases more calories relative to the time invested in their acquisition (Bettinger et al. 2006; Sturm et al. 2016). In this paper, we explore the following research question: How was ceramic technology used by small-scale mobile societies in the highlands of northwestern Patagonia?
Tafonomía actualística longitudinal de endoesqueleto y exoesqueleto de Zaedyus pichiy y de cáscar... more Tafonomía actualística longitudinal de endoesqueleto y exoesqueleto de Zaedyus pichiy y de cáscaras de huevos de Rheidae en un contexto controlado
Pumas are American top predators that commonly frequent places that may also be inhabited by huma... more Pumas are American top predators that commonly frequent places that may also be inhabited by humans. With the aim of contributing to the evaluation of the accumulating processes and agents of vertebrate remains of archaeological and paleontological sites, we analyzed a modern puma scat-derived vertebrate bone assemblage from an area of the central Monte Desert, one of the most arid regions of South America. We evaluated the taphonomic signature of vertebrate remains recovered in such scats without discriminating among the different types of fauna, which strengthens this taphonomic contribution. Despite the high availability of domestic and exotic fauna from livestock fields in the surroundings of the area, the assemblage was dominated by typical native small and medium-sized fauna from xeric environments of the Monte biome. The armadillo Zaedyus pichiy was the most frequent taxon, followed by the caviid rodents Microcavia maenas and Galea leucoblephara, and the Tinamidae Eudromia elegans. The most remarkable taphonomic signatures are high breakage; a high proportion and degree of elements with evidence of digestion; and a low number of tooth marks. We find a good proportion of identifiable specimens, considering the previous assumptions on the extreme destruction of felid scat-derived vertebrate bone assemblages. A first assessment was made of specimens little known from a regional taphonomic perspective, such as armadillo osteoderms or bird remains. The taphonomic analysis of this multi-taxa accumulation enables a solid evaluation of vertebrate bone assemblages from archaeological and paleontological sites.
Many cultural and natural processes form the archaeological record. Taphonomy, the study of the t... more Many cultural and natural processes form the archaeological record. Taphonomy, the study of the transition of organic matter from living contexts (the biosphere) to geological contexts (the lithosphere), aids in understanding how agents and processes affect skeletal remains in the archaeological record. In this paper the results of an actualistic taphonomic study on deposition of bones in open-air and cave contexts in the high elevation Andes Mountains are presented. Results indicate that within the first three months after deposition many bones are displaced or removed from sites and that the agents that act in each context are different. Horizontal displacement of bones from their deposited locations is limited in the cave context but is dominant in the open air site. Carnivores appear to be responsible for moving bones in open-air contexts, and rodents appear to displace bones vertically in the cave context. Such naturalistic experiments are important in particular areas of the w...
En este trabajo se presentan los resultados del análisis de cuatro sitios arqueológicos localizad... more En este trabajo se presentan los resultados del análisis de cuatro sitios arqueológicos localizados en los valles cordilleranos de altitud intermedia del río Diamante: El Perdido 1, El Perdido 4, El Perdido 5 y HI95.Se utiliza la información de materiales arqueológicos recolectados en superficie y de sondeos estratigráficos realizados en cada uno de estos sitos. El objetivo del trabajo es caracterizar el tipo de asentamiento y evaluar si hubo un uso diferencial de este espacio. Se busca, a su vez, evaluar cambios a lo largo del tiempo y entre sitios analizados. En este sentido, se encontraron diferencias en la intensidad de uso de cada uno de estos sitios. El Perdido 1 se presenta como el sitio con mayor intensidad de uso y mayor diversidad artefactual, por el contrario, HI95 es el que posee menor intensidad de uso. Para evaluar las diferencias en la intensidad de uso de cada sitio se consideró la disponibilidad de materias primas líticas y la localización de las mismas. En cuanto a...
ICAZ is one of the most prestigious scientific events in archaeological science; it is being held... more ICAZ is one of the most prestigious scientific events in archaeological science; it is being held in the southernhemisphere for the first time.
Roughly 1000 scholars will meet in southern Mendoza to discuss the latest theoretical and methodological advances in zooarchaeology and to present recent findings from around the world.
Nos complace anunciar las fechas y sede de las VI Jornadas Arqueológicas Cuyanas (VI JAC), organi... more Nos complace anunciar las fechas y sede de las VI Jornadas Arqueológicas Cuyanas (VI JAC), organizadas por el Museo de Historia Natural de San Rafael, UTN Facultad Regional San Rafael y IANIGLA-Grupo Vinculado San Rafael. Las mismas se llevarán a cabo entre los días 29, 30 de Septiembre y 1º de Octubre del corriente año. LOS ESPERAMOS!
Revista del Museo de Antropología 2(1): 169-180, Córdoba, Argentina, 2009
Las medidas obtenidas a partir de huesos del esqueleto apendicular de camélidos sudamericanos han... more Las medidas obtenidas a partir de huesos del esqueleto apendicular de camélidos sudamericanos han sido utili- zadas en los últimos años como insumo básico para interpretar distintos aspectos relacionados con su asignación especifica, manejo de rebaños y estrategias económicas, entre otros. La forma y el tamaño de los huesos han sido interpretados como el resultado de distintas fuerzas asociadas a distintos tipos de restricciones ambientales o modificaciones producto del manejo humano. Esto es de gran importancia a la hora de interpretar la historia de la relación humano-camélido, dado que el registro material obtenido en depósitos arqueológicos posee variados restos a través de los cuales se pueden reconstruir diversas situaciones ocurridas en el pasado, tanto a nivel de paleo-economías o paleoambientes. Gran parte de estas interpretaciones se han basado en escasas medidas de estándares moderno. Por ello, este trabajo tiene como objetivo presentar datos métricos obtenidos de individuos contemporáneos de camélidos sudamericanos y que han sido considerados relevantes para su uso como material comparativo. Con esto se intenta evaluar desde una mirada crítica el uso de estándares locales y no locales para la asignación específica de muestras arqueológicas. Con el fin de evaluar la variabilidad en la forma y el tamaño de las primeras falanges se aplica el Análisis de Componente Principal y de Conglomerados (UPGMA). Para ello se toman en cuenta diferencias de tamaño, forma y procedencia geográfica con el fin de observar el peso aportado por cada variable en la conformación de esta muestra. Como resultado se concluye que el uso de ambas técnicas más la procedencia geográfica de las muestras modernas permite una definición por especie de grano más fino.
Palabras clave: camélidos sudamericanos, osteometría, esqueleto postcraneal, falange proximal, variabilidad, estándares comparativos.
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Papers by Clara Otaola
historical significance as a vital resource for Patagonian hunter–gatherer societies.
Despite the species' cultural and ecological importance, the historical population
dynamics of R. pennata remain poorly understood. Although present in the archaeological
record, its abundance is not consistently documented and the reasons remain
unclear. This study investigates the late Holocene population trends of R. pennata
using ancient DNA analysis. By analyzing complete mitochondrial genome sequences
from dated archaeological specimens, we reveal a significant population increase
from 700 to 500 years Before Present (BP), followed by a period of relative stability
from 500 to 300 years BP. Subsequently, a subtle decline in population size is
observed, coinciding with the arrival of European settlers; however, due to considerable
uncertainty in population estimates, definitive conclusions regarding this decline
are challenging to make. Historical records indicate heightened rhea hunting during
this period, coterminous with a decrease in the abundance of rhea eggshell fragments.
It is suggested that climatic factors may have influenced these population
dynamics, particularly favoring rhea population growth from 700 to 500 years
BP. This study contributes to our understanding of the historical ecology and humanrhea
interactions in Patagonia, emphasizing the importance of interdisciplinary
approaches in reconstructing past population dynamics.
historical significance as a vital resource for Patagonian hunter–gatherer societies.
Despite the species' cultural and ecological importance, the historical population
dynamics of R. pennata remain poorly understood. Although present in the archaeological
record, its abundance is not consistently documented and the reasons remain
unclear. This study investigates the late Holocene population trends of R. pennata
using ancient DNA analysis. By analyzing complete mitochondrial genome sequences
from dated archaeological specimens, we reveal a significant population increase
from 700 to 500 years Before Present (BP), followed by a period of relative stability
from 500 to 300 years BP. Subsequently, a subtle decline in population size is
observed, coinciding with the arrival of European settlers; however, due to considerable
uncertainty in population estimates, definitive conclusions regarding this decline
are challenging to make. Historical records indicate heightened rhea hunting during
this period, coterminous with a decrease in the abundance of rhea eggshell fragments.
It is suggested that climatic factors may have influenced these population
dynamics, particularly favoring rhea population growth from 700 to 500 years
BP. This study contributes to our understanding of the historical ecology and humanrhea
interactions in Patagonia, emphasizing the importance of interdisciplinary
approaches in reconstructing past population dynamics.
Roughly 1000 scholars will meet in southern Mendoza to discuss the latest theoretical and methodological advances in zooarchaeology and to present recent findings from around the world.
Palabras clave: camélidos sudamericanos, osteometría, esqueleto postcraneal, falange proximal, variabilidad, estándares comparativos.