Ongoing fieldwork at the coastal site of Northern River Lagoon (NRL) in northern Belize, a specialized saltmaking community, has revealed a consumer relationship with the large, inland, stone-tool-producing center of Colha during the Late to Terminal Classic. Artifact distribution suggests that this economic partnership involved the movement of salt, salted products, and trade goods to Colha in exchange for stone tools. This inland–coastal partnership was enhanced by a shared ideology reflected in the iconography of identical Palmar Orange-polychrome plates. The presence of the ideologically imbued plates in both elite and nonelite contexts suggests they were intended to strengthen group allegiance and reinforce territorial boundaries during this troubled time. This study stimulates new insights into the structure of ancient Maya coastal–inland interaction spheres in northern Belize, thereby facilitating comparisons between local areas within a regional context.

Aztec images of decapitated goddesses link the symbolism of astronomy with politics and the seasonal cycle. Rituals reenacting decapitation may refer to lunar events in the context of a solar calendar, providing evidence of a luni-solar calendar. Decapitation imagery also involves metaphors expressing the rivalry between the cults of the sun and the moon. Huitzilopochtli's decapitation of Coyolxauhqui can be interpreted as a symbol of political conquest linked to the triumph of the sun over the moon. Analysis of Coyolxauhqui's imagery and mythology indicates that she represents the full moon eclipsed by the sun. Details of the decapitation myth indicate specific links with seasonal transition and events taking place at dawn and at midnight. Other decapitated goddesses, often referred to as earth goddesses with “lunar connections,” belong to a complex of lunar deities representing the moon within the earth (the new moon). Cihuacoatl, a goddess of the new moon, takes on threatening quality when she assumes the form of a tzitzimime attacking the sun during a solar eclipse. The demonic new moon was greatly feared, for it could cause an eternal solar eclipse bringing the Aztec world to an end.

The background, research design, structure, personnel, and history of investigations of the Vanderbilt Petexbatun Archaeological Project are summarized and critiqued. The major findings of each of the dozen subprojects of this multidisciplinary investigation of Maya civilization in the southwestern Peten region of Guatemala are reviewed. Subproject results include important new evidence on Classic Maya history, warfare, ecology, nutrition, cave ritual, social organization, and trade. These are summarized with particular emphasis on the implications of the Petexbatun findings for theories of the decline of southern lowland Maya civilization at the end of the Classic period.

From 1989 to 1996, excavation and surveys were carried out at dozens of sites and intersite areas in the southwestern Peten by the Defensive Systems Subproject of the Vanderbilt Petexbatun Regional Archaeological Project and by subsequent related Vanderbilt investigations. The excavations and analyses explored fortification systems, related settlement, and artifactual evidence. Beginning at about a.d. 760, the major centers of the Classic Maya civilization in the Petexbatun region were fortified by a massive expenditure of labor on defensive walls of masonry, usually surmounted by wooden palisades. As warfare accelerated, major centers and later even small hilltop villages were located in highly defensible positions and were fortified by walls, palisades, moats, and baffled gateways. Despite these efforts, all major centers were virtually abandoned by the early ninth century. By a.d. 830, only the island fortress of Punta de Chimino and a very reduced and scattered population remained in the Petexbatun region.

The Petexbatun region has a series of upland ridges surrounded by lowland wetlands. In Preclassic times, ancient Maya peoples began colonizing the region along waterways. Although few in number, they cleared large areas of upland tropical forest for agriculture and induced significant soil erosion. Population contracted in the region during the Early Classic, and mature tropical forest growth returned. During the Late Classic, population expanded rapidly across the region, forest clearance resumed, and desirable, intensively cultivated, upland areas were divided by an elaborate wall system. Upland agriculture during the Late Classic included the use of several types of terracing that significantly checked soil erosion during this period. Considerable variation may have existed between the urban agriculture practiced in the region's three major centers—Dos Pilas, Tamarindito, and Aguateca.

This paper reviews bioarchaeological research that aimed to test the biological correlates of ecological explanations for the Maya collapse using human skeletal remains from five sites in the Pasión region. Stable isotope ratios of bone collagen and alkaline earth ratios in bone minerals do not support the expectation of increased reliance on maize and declining meat consumption during the final years of Pasión occupation. Moreover, skeletal pathology does not illustrate any increment in anemia, infectious disease, or dental growth disruption that is predicted to have been a consequence of high population density and deteriorating nutrition. Instead, changes in the social distribution of foods during the Terminal Classic supports the mounting evidence that the Pasión collapse was fueled more by sociopolitical transformations than environmental ones.

The typological, modal, and chemical analyses of the pottery from the Petexbatun region of southwestern Peten, Guatemala, are used to establish a regional ceramic chronology and to assess three theories used to explain the Classic Maya collapse of the ninth and tenth centuries a.d. The three explanations are based on: (1) foreign invasion; (2) commercialization; and (3) internal warfare. Each of these theories suggests different changes in the regional ceramic-production and -exchange systems of the Petexbatun. Shifts in the ceramic production system are monitored using a standardization study, while instrumental neutron-activation analysis (INAA) is used to model changes in interregional exchange. The results of these analyses indicate that there was a continuity in the ceramic assemblage from the Late Classic Nacimiento phase (a.d. 600–830) to the Terminal Classic Sepens phase (a.d. 830–950). Together with little change in architectural, mortuary, and other artifactual styles, this finding suggests that no foreign groups invaded the Petexbatun region, and therefore did not lead to the collapse in the Pasion region. The small decreases in pottery standardization and the minor shifts in interregional exchange do not support the second theory that a major reorganization of Maya economy undercut the power base of the Maya elite class. On the other hand, these small decreases in standardization and in the scale of exchange do support the third theory, which suggests that internal warfare between the regional polities disrupted exchange, leading to more localized production. The stability of the ceramic production and exchange systems in the Petexbatun region throughout the collapse also suggests that the political and economic systems were largely disconnected. These findings suggest that internal political processes leading to an increase in competition and to intensified warfare were important factors in the Classic Maya collapse of the Petexbatun region in Peten, Guatemala.

Three field seasons of extensive residential archaeology at Dos Pilas, Peten, Guatemala, provide important data for the examination of ancient Maya social structure and the Classic Period collapse in the Petexbatun region. A sampling strategy guiding excavations in structures of different size and architectural configuration enables us to reconstruct the multifaceted, segmented nature of Maya social inequalities and helps to elucidate the effects of the collapse on the lives of people of various socioeconomic ranks and statuses. Other significant findings of the project include hieroglyphic vessels and stone sculptures in nonroyal elite domestic compounds, postcollapse occupation in the settlement, as well as continued craft production and interregional trade into Terminal Classic times and after elite abandonment of the site. The results of household archaeology at Dos Pilas, which demonstrate that elites were affected first and foremost during the collapse, support theories of intensified elite competition, socio-political instability, and warfare for the Maya downfall in the Petexbatun Region, and not environmental degradation or breakdowns in interregional trade.

Arroyo de Piedra occupies a strategic position between the sites of Dos Pilas and Tamarindito, the dominant polities in the Petexbatun region. Temples, palaces, sculptured monuments, quarries, and a defensive wall reflect the importance of this small site. Archaeological and epigraphic investigations conducted by Vanderbilt University from 1990 to 1994 demonstrate that Arroyo de Piedra was founded and ruled by members of the royal family of Tamarindito during the Early Classic. In the Late Classic, Arroyo de Piedra was absorbed by the expansionistic Dos Pilas dynasty through a matrimonial alliance. The marriage was apparently imposed by means of coercion as suggested by evidence of intentional destruction of local sculpture. The center was abandoned during the Terminal Classic, after the fall of Dos Pilas.

The archaeological site of Tamarindito is located on an elevated escarpment that gives it a wide panoramic view of various distances all around, especially toward the northeast in the direction of the Río Petexbatun and the lake with the same name, in addition to the well-known, important archaeological site of Seibal. Tamarindito is 7 km east of Dos Pilas and 7 km northwest of Aguateca. It is one of the most important sites of the Petexbatun region and the capital of the most ancient polity of the region.

Archaeological investigations at Aguateca, Guatemala, by the Petexbatun Regional Archaeological Project have provided clues to the intriguing sequence of the downfall of this Maya center. The earliest substantial occupation at Aguateca dates to the Late Preclassic period. After very little presence during the Early Classic period, Aguateca rapidly grew into a densely occupied center, probably at the beginning of the eighth century a.d. Migration from other areas may have contributed to this rapid population growth. In the late eighth century, extensive defensive walls were constructed, most likely as a response to intensified warfare. Despite this defensive effort, Aguateca was finally attacked and brought down by enemies probably at the beginning of the ninth century. The center appears to have been almost completely abandoned soon after this event. This reconstructed sequence confirms other evidence of the Petexbatun Project that intensified warfare played an important role in the Classic Maya collapse.

The Petexbatun Regional Cave Survey (PRCS) is the first large cave study to be undertaken as part of a major archaeological expedition. The survey's primary objective was assessing the extent to which surface architecture at Dos Pilas was configured by features in the sacred landscape. All three of the major architectural complexes at the site had a direct relation to caves, and a number of important secondary buildings and even residential units were deliberately laid out to incorporate caves. Excavation revealed evidence of Preclassic utilization of all of the major caves, indicating that their status as sacred landmarks had been established long before the eighth century florescence of the site. The importance of the caves in site configuration was mirrored in the artifact assemblage. Despite the survey's much smaller size, the cave investigations recovered 20–50% more of the overall assemblage at Dos Pilas in an array of artifact categories. A review of the archaeological literature suggests that the importance ascribed to caves at Dos Pilas in both site configuration and local economy can be found elsewhere and probably reflects a much wider pattern of utilization.