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The initial colonization of the Americas remains a highly debated topic 1 , and the exact timing of the first arrivals is unknown. The earliest archaeological record of Mexico—which holds a key geographical position in the Americas—is poorly known and understudied. Historically, the region has remained on the periphery of research focused on the first American populations 2 . However, recent investigations provide reliable evidence of a human presence in the northwest region of Mexico 3 , 4 , the Chiapas Highlands 5 , Central Mexico 6 and the Caribbean coast 7 – 9 during the Late Pleistocene and Early Holocene epochs. Here we present results of recent excavations at Chiquihuite Cave—a high-altitude site in central-northern Mexico—that corroborate previous findings in the Americas 10 – 17 of cultural evidence that dates to the Last Glacial Maximum (26,500–19,000 years ago) 18 , and which push back dates for human dispersal to the region possibly as early as 33,000–31,000 years ago. The site yielded about 1,900 stone artefacts within a 3-m-deep stratified sequence, revealing a previously unknown lithic industry that underwent only minor changes over millennia. More than 50 radiocarbon and luminescence dates provide chronological control, and genetic, palaeoenvironmental and chemical data document the changing environments in which the occupants lived. Our results provide new evidence for the antiquity of humans in the Americas, illustrate the cultural diversity of the earliest dispersal groups (which predate those of the Clovis culture) and open new directions of research. Chiquihuite Cave (Zacatecas, Mexico) provides evidence of human presence in the Americas between about 33,000–31,000 and 14,000–12,000 years ago, and expands the cultural variability known from sites of this date.

While debates have raged over the relationship between trance and rock art, unambiguous evidence of the consumption of hallucinogens has not been reported from any rock art site in the world. A painting possibly representing the flowers of Datura on the ceiling of a Californian rock art site called Pinwheel Cave was discovered alongside fibrous quids in the same ceiling. Even though Native Californians are historically documented to have used Datura to enter trance states, little evidence exists to associate it with rock art. A multianalytical approach to the rock art, the quids, and the archaeological context of this site was undertaken. Liquid chromatography–mass spectrometry (LC-MS) results found hallucinogenic alkaloids scopolamine and atropine in the quids, while scanning electron microscope analysis confirms most to be Datura wrightii. Three-dimensional (3D) analyses of the quids indicate the quids were likely masticated and thus consumed in the cave under the paintings. Archaeological evidence and chronological dating shows the site was well utilized as a temporary residence for a range of activities from Late Prehistory through Colonial Periods. This indicates that Datura was ingested in the cave and that the rock painting represents the plant itself, serving to codify communal rituals involving this powerful entheogen. These results confirm the use of hallucinogens at a rock art site while calling into question previous assumptions concerning trance and rock art imagery.

Advanced 2-D and 3-D computer visualizations are increasingly being used for recording and documentation, analysis, dissemination, and public engagement purposes. Recent technological advances not only considerably improve data acquisition, processing, and analysis but also enable easy and efficient online presentation. This article evaluates the contributions of advanced 2-D and 3-D computer visualization and discusses the potential of 3-D modeling for recording basketry technology and documenting the state of preservation of baskets. It explores the available analysis, integration, and online dissemination tools, using as case studies recently excavated baskets from Cache Cave in southern California. Results indicate that the proposed methodology, which incorporates reflectance transformation imaging visualizations and photogrammetric 3-D models, which are further processed using 3-D modeling software and integrated analysis tools and then transformed to a Web-based format, is a useful addition to the basketry analysis toolkit. Visualizaciones computacionales avanzadas 2-D y 3-D están siendo usadas con mayor frecuencia para registrar, documentar y analizar materiales con fines de divulgación. Recientes avances tecnológicos han posibilitado el mejoramiento en la toma de los datos, así como también, ha mejorado el procesamiento y la presentación en línea de éstos. El objetivo central de este artículo es evaluar las contribuciones de las visualizaciones computaciones 2-D y 3-D para, más adelante, discutir el potencial que el modelaje 3-D tiene, no sólo para el registro de la tecnología cestera, sino también para documentar el estado de preservación en el que se encuentra el material. Así, exploraremos las diferentes herramientas tecnológicas para el análisis y la integración de datos, que se encuentran disponibles en línea. Como caso específico, se utilizaran las cestas recientemente excavadas provenientes de la Cueva Cache, localizada en el sur de California. Resultados preliminares de esta metodología indican que procesar la imagen utilizando un software para modelar en 3-D, acompañado del uso de otras herramientas integradas de análisis y la posterior transformación de la imagen a un formato para Web, resultan un kit necesario e útil para el análisis de la cestería.