The city of Teotihuacan (AD 1–550) was a major multiethnic urban center that attracted migrants from as far away as west Mexico and the Maya region. Past research in the Tlajinga district at Teotihuacan using oxygen isotopes from human remains estimated that nearly 30% of the population of Tlajinga 33, a single apartment compound, were migrants. This study takes a dual-isotope approach (87Sr/86Sr and δ18Op) to reevaluate the proportion of in-migration at Tlajinga and includes data from two additional apartment compounds, Tlajinga 17 and 18 (n = 23). New results indicate that migrants comprised ~45% of the Tlajinga population. Previously acquired radiocarbon dates combined with mortuary and isotope data suggest that immigration to Tlajinga was highest during the first centuries of compound occupation. Nevertheless, migration was a continual process throughout its history. Additionally, a new finding suggests that residents of Tlajinga 33 ingested foods with higher 87Sr/86Sr ratios than did those of Tlajinga 17 and 18. We hypothesize that the incorporation of imported lime for the nixtamalization process skewed the 87Sr/86Sr ratios of human remains, a potentially important finding for future studies at Teotihuacan.

Investigations of the Proyecto Arqueológico Tlajinga Teotihuacan (PATT) in 2019 focused on the southern neighborhood center of this cluster of non-elite residences in the southern periphery of the ancient Mexican metropolis. Our objective was to better understand the social infrastructure of public space within the district and how it tied its inhabitants together. Our methods included excavations at two large architectural complexes, geophysical prospection of these and adjacent structures and plazas, and chemical residue analysis of floors and sediments. They revealed architecturally elaborate complexes decorated with mural painting that appear to have been the loci of civic-ceremonial activities. Materials from the excavated portions of the complexes are inconsistent with residential uses, although it is possible that local elites lived elsewhere in the complexes or in others located nearby. The investigations therefore demonstrate that the semipublic spaces of neighborhood centers were distributed as distantly as this periphery of Teotihuacan and could be as elaborate as those in the urban epicenter, underscoring the city's more muted social inequality.

Teotihuacan's Tlajinga district is a cluster of neighborhoods on the southern periphery of the city best known for earlier investigations at Compound 33:S3W1. New research includes excavations at two other apartment compounds and along the southern extension of the Street of the Dead. Excavation contexts, major finds, chronology, and preliminary interpretations are the subject of this article. We highlight evidence attesting to a major obsidian-blade workshop at Compound 17:S3E1, offerings, and other features at that compound and Compound 18:S3E1, and the tempo and processes of urbanization viewed through well-recorded stratigraphic sequences of the compounds and the Street of the Dead. We conclude that significant occupation began in the Miccaotli phase, but it was not until some point in the Early Tlamimilolpa phase that the dominant housing type became apartment compounds; the continuation of the axis of Street of the Dead in the district was accomplished by excavating in the volcanic tuft substrate (tepetate) and could have been undertaken by the inhabitants of the district themselves; and the presence of items such as a sculpted stone face, marine shell, and polychrome pottery demonstrates that commoners at Teotihuacan enjoyed some access to finer items within the interregional economy.

The original research by the Teotihuacan Mapping Project (TMP) identified a large number of obsidian workshops within Teotihuacan based on surface concentrations of production debris. Clark (1986b) questioned the validity of these identifications and called for subsurface excavation to confirm the presence of in situ workshop locales. This article summarizes the results from the excavation of one of the obsidian workshops identified in the Tlajinga district of Teotihuacan at Compound 17:S3E1 (Compound 17). We describe the excavations, discuss the lithic technology, and examine the subsurface contexts in terms of what they tell us about in situ obsidian craft activity. Excavations confirm that Compound 17 was a locus of large-scale obsidian craft production during the Classic period. While only a single test case, these results suggest that surface remains at Teotihuacan can be a useful guide in identifying craft production areas when they are confirmed through subsurface testing.

Estudios geofísicos, técnicas de sensores remotos y realización de mapas topográficos con GPS diferencial y vehículos aéreos no tripulados (VANT) han proporcionado una mejor comprensión de la organización espacial de los conjuntos departamentales y barrios en Teotihuacán. Nuestras investigaciones demuestran que en contraste con el mapa producido por el Teotihuacan Mapping Project (TMP) (Millon et al. 1973), el distrito de Tlanjinga es más rectangular y está más formalmente organizado, mientras que los conjuntos individuales tienen formas más irregulares, como lo había mostrado la excavación de Tlajinga 33 (Widmer y Storey 1993). Esto difiere de los nítidos cuadrados y rectángulos interpretados por las reconstrucciones arquitectónicas del TMP. El estudio de las imágenes satelitales mostró manchas blanquecinas en el terreno que parecen corresponder con áreas elevadas del mismo y con la desintegración de los aplanados de cal, destruidos por el tiempo y el trabajo agrícola. También verificamos la continuación del trazo de la Calzada de los Muertos que cruza este distrito mediante la modificación del relieve ocasionada por la excavación realizada en la toba volcánica subyacente (tepetate).

Site-wide, assemblage-based lithic analyses help to elucidate community dynamics including variability in domestic economies, technological skill and decision making, exchange networks, and ritual practices. In this study we present the results of an analysis of over 36,000 lithic artifacts from the site of La Laguna, Tlaxcala. We compare Middle to Late Formative period (ca. 600–400 b.c.) and Terminal Formative period (ca. 100 b.c.–a.d. 150) deposits to examine transformations associated with urbanization and state formation during this interval. The residents of La Laguna had relatively equal and ample access to obsidian, and most production was organized independently by households. We identify blade production zones and variability in consumption patterns suggestive of different domestic, communal, and ceremonial activities. The introduction of bloodletters, elaborate large bifacial knives, and zoomorphic eccentrics to the Terminal Formative assemblage may indicate the emergence of higher statuses, new social roles, and militaristic symbolism during this period.

The households of Formative period central Mexico represent critical loci for understanding major social transformations during a millennium (900 b.c.– a.d. 100) that witnessed the expansion and contraction of several macro-regional stylistic and economic networks, formalization of enduring political and religious institutions, and initial urbanization and state formation. Households and their constituent members used style to articulate important elements of their identity through practices of group consumption and personal adornment. In this study we consider style within the context of ceramic serving vessels and portable adornments primarily from sites in the state of Tlaxcala. We evaluate the manner in which dimensions of stylistic expression in these material goods contributed to shifting conceptualizations of household and individual identity and their articulation with community and supra-community social networks, noting the generally collective or affinitive manipulation of styles with means of socially differentiating age, status, and other dimensions of identity.

Recent work at La Laguna in Central Mexico provides an excellent illustration of the way in which information from architecture, food remains, ceramic vessels and chemical signatures can be brought together to demonstrate communal feasting associated with specific structures and public spaces. Structure 12M-3 contained a range of evidence indicative of food preparation and consumption. Ritual effigy vessels depicted deities connected with food and fertility, and fire and the hearth. Taken together, the several lines of evidence indicate that Structure 12M-3 was a special building, located directly behind the main temple and devoted to the preparation and production of communal feasts that were held in the adjacent plaza. This provides new insights into community life in the urban centres of early Mesoamerica.

Urbanization of the world's first cities involved the social integration of greater scales of community membership as well as the social differentiation of individuals along the continua of wealth, power, and occupational specialization that define urban landscapes. This article considers the causal role of public ritual in these processes during the period of incipient urbanism in central Mexico (c. 600 BC–AD 100) by examining temple and plaza offerings at La Laguna, a town within an urbanizing cultural landscape whose inhabitants participated in the transformative exchanges that resulted in urban state capitals such as Teotihuacan.

Two Terminal Formative (ca. 100 B. C.–A.D. 100) domestic areas of La Laguna, Tlaxcala, are compared to examine variability in residential structures, assemblages, and practices, and their correlation to status differences at this midsize regional center during the period of initial central Mexican urbanization and state formation. Combining multiple lines of evidence, the study assesses the applicability of previous frameworks for investigating household status to this particular community. It demonstrates significant differences between elite and commoner residences in architectural elaboration, labor mobilization, access to certain foreign goods, and particular ritual practices, but general similarities in domestic economies and more restrained differentiation informs of personal adornment and domestic ritual. These conclusions are consistent with demarcated lineage ranking but relatively minor wealth accumulation by a more rural elite located peripherally to larger cities and polities.

Obsidian prismatic blades were widely traded across Mesoamerica during the Early and Middle Formative periods. However, it was not until the Late Formative period (400 b.c.—a.d. 100) that prismatic blade cores began to be exchanged extensively. Although it is generally accepted that the trading of blades preceded the trading of cores by almost 1,000 years, little is know about the structure of blade trading during the Early and Middle Formative periods. We describe three distributional models for the trade of obsidian prismatic blades: whole-blade trade, processed-blade trade, and local-blade production. These models were evaluated using obsidian consumption data from Oaxaca, the Basin of Mexico, and Tlaxcala. The results indicate that Formative period blade trade involved different forms over time and space.

The expansionary strategies of Teotihuacano political leaders involved the large-scale manufacture of weaponry and the production of ceremonial items representative of a coherent suite of symbols expressing themes of warfare and sacrifice. Recent excavations at the Moon Pyramid demonstrate that such production activities were undertaken next to the monument, where obsidian was reduced into dart points and eccentrics linked to militarism and sacrificial practices in the art and archaeology of the city. These craft production activities were likely directly administered by state functionaries and formed part of the physical and ideational bases of state political authority. The finished products served as means of direct military coercion and symbolic reification of state authority, materialized through the militaristic offering complexes within the major temples of the city. This study presents a detailed technological analysis of the production activities and contextualizes their social significance by examining their symbolic manipulation in the art and sacrificial offerings of Teotihuacán.

Investigations into the evolution of early religious institutions should emphasize how the ritual manipulation of symbolically charged objects generated shared understandings regarding divine entities among religious communities of practice. This study demonstrates that the origins of two distinctively central Mexican deities—the Old God of Fire and the Storm God—can best be understood through contextual analysis of effigy vessels depicting them during later Formative periods (ca. 600 b.c.–a.d. 100). By presenting new examples of such effigy vessels and assembling contemporary counterparts from other central Mexican sites, we can better appreciate the Formative religious integration of the region and its legacy for the religious systems of later societies. Specifically, the primacy of the Old God of Fire and the Storm God to Aztec dedicatory offerings, and the private/domestic associations of the former and public/monumental associations of the latter at Teotihuacan were elaborations on patterns apparent in Formative ritual practices.

This report presents the results of a compositional study using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to examine central Mexican obsidian procurement at four sites dating to the Formative and Classic periods. The study demonstrates LA-ICP-MS to be a highly accurate obsidian sourcing technique, with results that are directly comparable to instrumental neutron activation analysis. It documents a shift circa 600 B.C. in which Middle Formative villages in Tlaxcala began to obtain obsidian almost exclusively from sources located in the Mesa Central, when they had previously obtained approximately 50 percent from Mesa Central sources and 50 percent from sources located in the Sierra Madre Oriental. This shift broadly coincided with the development of large regional centers in Tlaxcala-Puebla and suggests a linkage between the local political evolution occurring at this time and increased interactions with the Mesa Central economic sphere, including the Basin of Mexico. Obsidian workshop dump deposits next to Teotihuacan’s Moon Pyramid, dating to a millennium later, demonstrate the continued reliance on predominantly Mesa Central sources but also diversified procurement that drew on several sources. The Teotihuacan deposits exhibit the preferential utilization of particular sources depending on the types of implements being produced.