The petrous portion of the temporal bone (often informally referred to as the "petrous bone") is a key element in human evolutionary studies due to its exceptional preservation of biomolecules and morphological information. Intensive and often redundant sampling raises concerns about sustainability and long-term conservation, however. Digital recording of morphology (micro-computed and medical tomography) can preserve what destructive sampling destroys, enabling future analyses, yet there have been concerns regarding its effect on biomolecular preservation. Here, we present a systematic observational assessment of whether micro-computed tomography (µCT)-a widely used tool for digital preservation-affects ancient DNA (aDNA) integrity in archaeological human petrous portions. We analyzed 93 archaeological samples from Argentina, of which 50 were µCT-scanned prior to molecular analysis and 43 were not. We compared six commonly used molecular parameters, including endogenous DNA content, read length, cytosine deamination patterns, and mitochondrial and nuclear contamination estimates. No statistically significant differences were observed between scanned and unscanned samples across these parameters (Mann-Whitney/Wilcoxon tests, p > 0.05). Although mitochondrial contamination estimates were marginally higher in scanned samples (p = 0.051), they largely remain below the widely accepted 5% threshold for genomic analysis. Moreover, this pattern was not observed when considering nuclear contamination. Within the limits of this non-paired design, these results suggest that µCT imaging, under the scanning parameters applied here, does not introduce large or systematic bias derived from disruptions in standard aDNA preservation metrics. Building on these observations and on our collaborative experience with the shared use of archaeological samples across complementary research lines, and given that our results show that µCT imaging under appropriate scanning conditions does not significantly compromise DNA preservation, we propose a sustainable, multi-step workflow that integrates biological profiling, osteobiography, imaging, and compositional pre-screening prior to molecular sampling. This approach aims to maximize the scientific information obtained from skeletal collections while minimizing destructive practices, thereby promoting ethical and sustainable research on irreplaceable anthropological remains, and fostering interdisciplinary collaboration.

ABSTRACT The human bony labyrinth has attracted increasing interest because of its taxonomic, evolutionary, and functional significance. Although sexual dimorphism has been reported in several aspects of the temporal bone, the extent to which sex, age, size, and allometry contribute to labyrinth shape variation remains poorly understood. Here, we investigated patterns of sexual shape variation in the human bony labyrinth using three-dimensional geometric morphometrics in a sample of 98 archaeological individuals from South America with known genomic sex. Centroid size and allometric effects were assessed in a subset of 90 individuals with comparable metric scaling. In addition to analysing the complete labyrinth, the cochlea and semicircular canals were examined separately to evaluate region-specific patterns of sexual shape variation. Principal Component Analysis showed extensive overlap between females and males, and overall labyrinth shape did not differ significantly between sexes. Males exhibited significantly larger labyrinths than females, and centroid size explained a small but significant proportion of overall shape variation. Regional analyses showed no evidence of significant sexual shape differences in the cochlea or in any individual semicircular canal when analysed separately. In contrast, the combined semicircular canal system exhibited subtle but significant sexual shape variation independent of centroid size, whereas morphological disparity did not differ between sexes. The geometric comparison of the female and male consensus configurations further showed that sexual shape variation was regionally heterogeneous. Whereas the cochlea exhibited a pattern of localized changes with low directional coherence, the semicircular canals displayed more coordinated regional shape changes. The male consensus also exhibited slightly higher canal circularity across all three semicircular canals, particularly the posterior canal, while differences in canal-plane orientation remained minimal. These findings demonstrate that sexual shape variation in the human bony labyrinth is subtle and anatomically partitioned among its components. Although significant sex differences in centroid size were detected across most anatomical regions, overall labyrinth shape and cochlear morphology were primarily influenced by allometry, whereas significant sex-related shape differences were detected only when the semicircular canals were considered as an integrated anatomical system. These findings demonstrate that sexual dimorphism in the human bony labyrinth is subtle but regionally heterogeneous, with the cochlea and semicircular canals exhibiting distinct patterns of shape variation, suggesting that these structures are influenced by different developmental, functional, and evolutionary processes.

The transition to agriculture was a transformative process in human history with wide-ranging demographic and social consequences1. Across South America, agriculture was adopted at different times and through diverse pathways, resulting in a mosaic of regionally distinct farming histories2,3. The Uspallata Valley, at the southern frontier of Andean farming, offers a unique opportunity to examine a case of late adoption of agriculture. Here we show that agriculture in the Uspallata Valley was adopted by local hunter-gatherers, as evidenced by genetic continuity between pre-farming and farming populations inferred from 46 newly sequenced ancient human genomes. These groups carried a distinct genetic component in Indigenous American diversity, indicating a unique population history in the region. Palaeodietary isotopes (δ13C/δ15N) reveal fluctuating maize intake consistent with flexible farming. Strontium isotopes (87Sr/86Sr) indicate the arrival of migrants from nearby regions between around 810-700 cal years BP, shortly before the Inka expansion. Genomic and isotopic analyses show that these migrants belonged to the same regional metapopulation as local groups, relied heavily on maize, probably moved in matrilineally organized family groups, exhibited stress markers (including malnutrition and diseases, such as tuberculosis, as confirmed by pathogen genomics) and experienced a long-term demographic decline. Our results suggest that these groups used social organization and migration as resilience strategies in the face of a multidimensional crisis.

While recent genomic and isotopic information show that migration has been pervasive along human history, southern Andean archaeology has largely overlooked its importance in shaping human trajectories of sociocultural change. Building on previous isotopic research that identified the presence of migrant farmers in the Uspallata Valley (Mendoza, Argentina), we present chronological and bioarchaeological results that help to characterize the timing and mode of human migrations in the southern Andes. The burials with migrants show the representation of the different age classes, including a high abundance of children, as well as both men and women, suggesting that family groups were likely involved. The Bayesian modeling of 16 direct dates for migrants indicates that these migrations started between 1210-1275 CE (median 1255 CE) and finished at 1320-1425 CE (median 1360 CE), indicating that there is nearly no overlap between the commencement of this migration phase and the southwards expansion of the Inka Empire. The model defines a diachronic process that lasted between 55 and 195 years, implying that migration to Uspallata was a multi-generational process that involved between two and eight generations (median of four generations). Our contextual, bioarchaeological and chronological evidence indicates that the conditions fostering migration to Uspallata were sustained through time, inviting to explore persisting push-pull dynamics acting during this period. 87Sr/86Sr results show that migration occurred across the daily territories of these groups and may have involved movement across social or ethnic frontiers.

We present the results of an archaeological survey conducted on segments of the southernmost transversal path of the Qhapaq Nan or Inca Road in NW Mendoza Province (Argentina). We suggest that this part of the road was connected to a complex set of related trans-Andean tracks. The evidence presented here suggests that the Inca simultaneously utilized the highland passes Cristo Redentor and Navarro, and that the latter could have been part of a ceremonial pathway leading to the Aconcagua Mount, the main regional apu/waca. We also propose that this complex was associated with other paths with logistic and ritual significance in the Tupungato and De las Vacas Rivers. Overall, the new results allow suggesting that the Inca applied policies of social control based on ideological means in this part of the southernmost expanse of the Tawantinsuyu. The sacralization of the highland pathways and their setting would have been a key component of these strategies.

This new project studies the diversity of socioecological niches across the agropastoral transition in the Andes, utilising a multi-isotope approach to track human territories and allocate subsistence tasks. During the agropastoral period, we discriminate different diachronic niches with varying extents of maize farming and altitudinal mobility.

Se presentan resultados de estudios arqueológicos realizados sobre segmentos del ramal transversal más meridional del Qhapac Ñan. Se propone que este ramal, ubicado en el NO de la provincia de Mendoza (Argentina), tuvo derivaciones que lo conectaban con una red compleja de vías de circulación inter-cordillerana. El registro obtenido permite inferir que los Incas usaron, en forma simultánea, los pasos Cristo Redentor y de Navarro y que este último pudo ser parte de un camino ceremonial que llevaba al cerro Aconcagua, apu/waca principal de la región. Se plantea también que generaron y/o mantuvieron otros caminos con función logística y ritual sobre los valles de los ríos Tupungato y de Las Vacas. Con esta nueva información se consolida la posibilidad de que los Incas hayan aplicado preferentemente, en este sector del extremo sur del Tawantinsuyu, políticas de dominación de tipo ideológico que llevaron a una sacralización de los caminos cordilleranos y sus entornos.

La movilidad es uno de los temas claves de la arqueología del sur de Sudamérica y ofrece el marco en el cual se visualizan múltiples aspectos de la organización económica y social pasada. Más allá de este interés, existen fuentes de variación a nivel de las historias de vida que resultan poco visibles en el registro arqueológico y han recibido poca atención. Sin embargo, el registro etnográfico global muestra que las historias de vida son claves y también lo habrían sido en escala arqueológica. Para conectar estas dimensiones, exploramos diferentes niveles de la movilidad, considerando esferas de movimientos cotidianos y disruptivos. Proponemos un modelo de base etnográfica que conecta formas generales de organización del parentesco con las historias de vida. Luego, exploramos una vía de contrastación del modelo mediante isótopos de estroncio (87Sr/86Sr), que permiten estudiar el rango geográfico de movimientos, y de isótopos estables (carbono y nitrógeno), que ofrecen un marcador de amplitud de nichos. Aplicamos este modelo a dos regiones del norte de la Provincia de Mendoza (Argentina): Barrancas, situada en las planicies orientales (2500-2000 años cal. AP), y Valle de Uspallata (1200-700 años cal. AP). El análisis permite evaluar la escala de movilidad diaria, la estabilidad en la vida de los individuos, la existencia de sistemas intensivos y extensivos de organización del parentesco y la incidencia de procesos de migración.

Palaeodemographic and isotopic analyses provide key information for understanding the composition and social dynamics of past human groups and within-population variation in diet and geographic range. The objectives of this study are to reconstruct the demographic structure of the Osario Potrero Las Colonias site, to strengthen its chronology and, by means of stable (delta C-13(col)., delta C-13(ap)., delta N-15) and strontium (Sr-87/Sr-86) isotopes, to assess the dietary composition and geographic place of residence of a random sample of individuals from the site. This is a multiple archaeological burial with radiocarbon dates between AD 1320 and 1450, which places it in a period of important changes in regional history, related to a demographic increase and the arrival of the Inka empire on its southern frontier (ca. AD 1400). The demographic composition of the site reveals a broad social group unique in the region due to the large number of individuals bur- ied, especially young children. Strontium isotopes indicate that the sampled individuals did not reside in Uspallata during the last years of their lives, and hence can be considered migrants, while stable isotopes indicate a predominant consumption of C-4 resources.

Since a few years ago, several studies have been carried out to analyze the impact of economic changes produced in the center-north of Mendoza during the late Holocene on the development of skeletal pathologies and stress patterns. This study presents the results of an analysis of spinal osteoarthrosis (OA) on 26 individuals belonging to six archaeological sites, considering the chronological (before and after 1000 BP) and geomorphological (Mountain and Plain) divisions proposed in previous investigations. A trend towards a greater development of OA, particularly in the dorsal and lumbar segments, was observed within groups associated with economies primarily based on hunting and gathering. By contrast, individuals belonging to later periods, associated with a greater intake of domesticated resources, and including Inka rule and contact with Spanish conquistadores, show lower incidence rates and severity. Our results add to the existing knowledge about OA in the different groups that inhabited the region during the late Holocene.

Mobility is a key issue in the archaeology of southern South America, providing a lens through which multiple aspects of past social and economic organization can be visualized. Beyond this focus, there are multiple sources of behavioral variation that have little archaeological visibility and are thus seldom considered. However, the global ethnographic record shows that these aspects play a key role which may have also been significative at the archaeological scale. To connect these analytical levels, we explore different dimensions of daily and anomalous-potentially disruptive-human mobility. We develop an ethnography-based model that centers on individual life histories and incorporates aspects of mobility and kinship organization. Building on this, we present a first archaeological evaluation based on strontium isotopes, which allows us to track paleomobility, and stable isotopes, providing insights on paleodiet and niche width. This is applied to two archaeological contexts from northern Mendoza Province (Argentina): Barrancas, located in the eastern lowlands (2000-2300 cal BP) and the Uspallata Valley, between the geological units of the Precordillera and Cordillera Frontal (1200-700 cal years BP). The analysis enables us to evaluate the scale of daily mobility, stability of life histories, existence of different forms of kinship organization, and the incidence of migration.

Las fracturas compresivas de los cuerpos vertebrales son una de las fracturas óseas más frecuentes en poblaciones actuales, produciendo secuelas crónicas en algunos casos severos. Aunque son también identificadas en restos humanos esqueletizados, son escasos los estudios detallados que incluyen muestras esqueletales extensas. Este reducido análisis de las fracturas vertebrales es también identificado en restos humanos de Argentina. El objetivo del presente trabajo es, entonces, analizar la prevalencia, distribución y posibles causas de fracturas de cuerpos vertebrales por compresión en una muestra de esqueletos humanos arqueológicos provenientes de poblaciones que habitaron el Centro-Norte de Mendoza durante el Holoceno tardío, considerando los métodos disponibles y su aplicación en estudios paleopatológicos. Estos datos permitirán aportar información para evaluar la existencia de patrones diferenciales de fracturas vertebrales relacionados con los cambios poblacionales reconocidos en la región. Se analizaron 598 vértebras de 27 individuos pertenecientes a 6 sitios arqueológicos, a través del análisis de la medición de la altura y las modificaciones de la morfología de los cuerpos vertebrales. La mayoría de los esqueletos afectados son hombres adultos medios, sin otras evidencias patológicas, por lo que la causa más probable en esos casos sean traumatismos axiales agudos. Se identificó una mayor frecuencia de fracturas en individuos correspondientes al periodo 1500 a 1000 años AP, periodo asociado a cambios culturales y económicos significativos en la región. Sin embargo, esta tendencia deberá ser evaluada a partir de muestras de mayor extensión en el futuro.

Desde hace unos años, en el Centro-Norte de Mendoza se han llevado adelante investigaciones que buscan analizar el impacto de los cambios de estrategias de subsistencia producidos durante el Holoceno Tardío y que incluyen el estudio de estos procesos sobre el desarrollo de diferentes patologías y patrones de estrés. En este trabajo se presentan los resultados del análisis de la osteoartrosis (OA) en la columna vertebral en 26 individuos pertenecientes a seis sitios arqueológicos, considerando la división cronológica (antes y después del 1000 AP) y geomorfológica (Montaña y Planicie) planteada en investigaciones previas. Se observó una tendencia a un mayor desarrollo de la OA, particularmente en los segmentos dorsal y lumbar, en momentos asociados a grupos de economías con un mayor aporte proveniente de la caza-recolección. Por el contrario, los individuos de periodos tardíos, asociados a un mayor consumo de recursos domesticados y que incluyen la dominación Inka y el contacto con colonizadores europeos, mostraron prevalencias menores y de poca severidad. Los resultados obtenidos contribuyen al conocimiento acerca de la OA en los grupos que habitaron la región durante el Holoceno Tardío.

Los análisis paleodemográficos e isotópicos ofrecen información contundentepara entender la com-posición y dinámica de los grupos humanos del pasadoyla variación dentro de la población en dietay rango geográfico. El presente trabajo tiene por objetivos reconstruir la estructura demográfica del sitioOsario Potrero Las Colonias, caracterizar la composición de la dieta de los individuos mediante isótoposestables (δ13Ccol,δ13Cap,δ15N) y su lugar de residencia a través de isótopos de estroncio (87Sr/86Sr).El sitioconsiste en una inhumación arqueológica múltiple ycuenta con fechas radiocarbónicas publicadas quelo posicionan en un período de cambios importantes de la historia regional (1320-1450 DC), relacionadocon un aumento demográfico y con la llegada del Imperio inka a su frontera sur (ca. 1400 DC).Lacom-posición demográfica del sitio da cuenta de un amplio grupo social en la región por la abundante cantidadde individuos enterrados, particularmente infantiles. Los resultados de87Sr/86Sr para una muestra aleatoriade siete individuos marcan que estos no fueron residentes en Uspallata los últimos años de su vida, sinoque se trataría de migrantes; mientras que losisótopos estables indican un consumo predominante derecursos C4. Estos resultados abren nuevas perspectivas de trabajo interdisciplinario para los Andes del sur.

Transcurridos cincuenta años de la publicación del trabajo “Arqueología del valle de Uspallata, Provincia de Mendoza” escrito por Juan Schobinger en la revista Relaciones, actualizamos la nómina de sitios arqueológicos y sumamos evidencias, datos e interpretaciones generadas desde entonces por diversos equipos de investigación. Se incluyen además aportes específicos de análisis cerámicos, líticos, del arte rupestre, isotópicos, bioarqueológicos, arquitectónicos, entre otros. El tiempo transcurrido desde la publicación original permite discutir cómo ha cambiado la periodización de las ocupaciones del valle y la forma de hacer e interpretar los patrones materiales en una de las principales áreas arqueológicas del Centro-oeste argentino.

Fifty years after Juan Schobinger published "Arqueologia del valle de Uspallata, Provincia de Mendoza" (Archaeology of the Uspallata Valley, Mendoza province) in the Relaciones research journal, we have updated the list of archaeological sites and added evidence, data, and interpretations produced by several research teams since then. Additionally, specific contributions of ceramic, lithic, rock art, isotopic, bioarchaeological and architectural analyses are included, among others. The time elapsed since the original publication allows us to discuss how the periodization of the valley occupations and the ways of making and interpreting material patterns have changed in one of the primary archaeological areas of midwestern Argentina.

We present isotopic and morphometric evidence suggesting the migration of farmers in the southern Andes in the period AD 1270–1420, leading up to the Inka conquest occurring ~ AD 1400. This is based on the interdisciplinary study of human remains from archaeological cemeteries in the Andean Uspallata Valley (Argentina), located in the southern frontier of the Inka Empire. The studied samples span AD 800–1500, encompassing the highly dynamic Late Intermediate Period and culminating with the imperial expansion. Our research combines a macro-regional study of human paleomobility and migration based on a new strontium isoscape across the Andes that allows identifying locals and migrants, a geometric morphometric analysis of cranio-facial morphology suggesting separate ancestral lineages, and a paleodietary reconstruction based on stable isotopes showing that the migrants had diets exceptionally high in C 4 plants and largely based on maize agriculture. Significantly, this migration influx occurred during a period of regional demographic increase and would have been part of a widespread period of change in settlement patterns and population movements that preceded the Inka expansion. These processes increased local social diversity and may have been subsequently utilized by the Inka to channel interaction with the local societies.