This study describes, illustrates, and applies an “eclipse family” representation for the cyclic timing of eclipses in Mesoamerica. This theoretical construct is based on daykeepers’ approach to divination, anchored in the divinatory calendar (DC); empirically, it emerges from data on the timing of eclipses in Lowland Mayan1 territory between 100 b.c.e. and 1500 c.e. drawn from Espenak and Meuss's (2007, 2009) eclipse canons.

An eclipse family consists of a sequence of stations on which an eclipse might be visible in Mesoamerica – one every 88 new or full moons for 170 to 200 years, restricted to one of three DC zones. Cyclic and linear time relationships among dates of eclipses follow from this representation: intervals between successive stations in concurrent families in the same zone, and between successive stations across zones; between successive families in a zone; and among the first or last stations of families, within and across zones.

One and only one eclipse-family representation fits the lunar stations of the Dresden Codex; its properties show that it is a solar eclipse table. In real time, the table pertains to a 405-month interval sometime between 1076 and 1148 c.e., most likely from April 19, 1083 c.e. to January 16, 1116 c.e.

The Ceibal-Petexbatun Archaeological Project has been conducting field investigations at the lowland Maya site of Ceibal since 2005. Previous research at this site by Harvard University allowed us to develop detailed research designs geared toward specific research questions. A particularly important focus was the question of how lowland Maya civilization emerged and developed. Comparison with contemporaneous sites in central Chiapas led us to hypothesize that the residents of Ceibal established a formal spatial pattern similar to those of the Chiapas centers during the Middle Preclassic period (1000–350 b.c.). Through excavations of important elements of this spatial pattern, including a probable E-Group assemblage and large platforms, we examined how the Ceibal residents participated in interregional interactions with Chiapas, the Gulf Coast, and other areas, and how construction activities and architecture shaped the course of social change.

The Maya of Copan, Honduras used Stela D, its altar, and the surrounding structures as a sundial to record time. Archaeological investigations show that wooden posts and stelae could have been used to measure time and to perform associated rites in the northern sector of the Main Plaza of the Copan Archaeological Park. We constructed a digital model of Stela D to study the shadows cast at different times of day and on different dates of the year, such as solstices, equinoxes, and solar zenith passages. The size and orientation of the shadows may have served as a time marker that ancient residents of Copan used to accurately track the tropical year. We also found evidence that supports the iconographic interpretation of an analogy between serpents’ bodies that adorn the figure of the ruler on Stela D and shadows and sun positions on dates of major solar events that form a solar calendar that counts years from winter solstice day.

The probable E-Group assemblage was a primary focus of our investigation at the lowland Maya center of Ceibal. Tunnel excavation into Structure A-20 (the western structure of this complex) demonstrated that the Ceibal residents built the earliest version (Structure Ajaw) by carving natural marl around 950 b.c. The earliest version of the eastern platform (Structure Xa'an) was also made at the same time out of the natural marl layer. Through a series of renovations, the western structure grew into a pyramidal shape, and later versions of the eastern platform were moved further to the east. In addition, excavations revealed numerous caches, many with greenstone axes, along the center line of the E-Group assemblage. These results show that a formal ceremonial complex was established at the beginning of occupation at Ceibal, and its construction and public events held there played an important role in the creation of a new community.

Members of the Proyecto Arqueológico de la Biosfera Calakmul under Carrasco's direction excavated the Cenote Style Group E-type complex at the Maya site of Calakmul, Campeche, Mexico. The Cenote Style refers to the plan of the E-Group with a series of three temples built onto a long narrow eastern range structure facing a western structure across a broad central plaza. Architectural data exist to evaluate this standardizing group's utility for observing solar events. Astronomical evidence for the function of this complex is presented and discussed. The overall orientation of Structures IVa, IVb, IVc, and VI is slightly east, 13° of true north, while a pair of doorways in Structure IVc align with the setting sun during the summer solstice point, despite the break in the buildings' floor-plan symmetry this represents.

Excavations in large platforms in the center of Ceibal revealed extensive early Middle Preclassic constructions. They consisted of extensive clay platforms that supported low basal structural platforms. Although the function of the earliest platform, Sulul, during the Real-Xe 1 and 2 phases (950–775 b.c.) is not clear, the one built during the Real-Xe 3 phase (775–700 b.c.) likely supported multiple residential buildings. The emphasis on elevating this domestic space above the natural land surface and the communal labor involved in these constructions indicate that they were most likely inhabited by an emergent elite. These places were continuously remodeled and used until the end of the Middle Preclassic. This new data from Ceibal contributes significantly to our understanding of the processes involved in the transition to a sedentary lifestyle and the development of social and political differentiation in the Maya lowlands.

This essay concludes the Special Section “Mesoamerican Cultural Astronomy and the Calendar.” In it, the themes Special Section authors address are put into both an anthropological and an astronomical context.

Archaeological investigations at the minor center of Caobal provide clues about local traditions of civic-ceremonial architecture as well as the relationship between these buildings and broader social and political transformations during the Preclassic period. The remains of pre-Hispanic Maya architecture represent a series of actions, decisions, and repeated practices, which contribute to long sequences of construction observed in the archaeological record. In particular, these data shed light on two major building campaigns that took place within Caobal's central precinct from about 850 b.c.–a.d. 250. By examining the materiality and temporality of minor temple architecture beyond primary centers of power, we examine how these buildings were constructed and, in turn, how these structures may have transformed the daily practices, identity politics, and religious values of pre-Hispanic Maya communities. Repeated construction of buildings in the temple precinct of Caobal provides a long and detailed archaeological record that allows us to reconstruct the history of material and social practices that shaped this local community beyond the Ceibal center.

This article discusses the results of my diachronic analysis of lithic artifacts collected around Ceibal, Guatemala, in order to elucidate one aspect of long-term changing patterns in the pre-Columbian Maya economic systems and warfare. The importation of large polyhedral obsidian cores and local production of prismatic blades began as the result of sociopolitical development in Ceibal during the early Middle Preclassic Real-Xe phase. El Chayal obsidian was heavily used during the early Middle Preclassic period, while San Martín Jilotepeque was the principal source in the late Middle Preclassic, Late Preclassic, and Terminal Preclassic periods, and El Chayal once more became the major source in Ceibal during the Classic period. There is increasing evidence of the production and use of chert and obsidian points in the central part of Ceibal during the Late and Terminal Classic periods, indicating elites' direct involvement in warfare. Although the spear or dart points were predominant weapons in Classic Maya warfare, the increase in both chert small unifacial points and obsidian prismatic blade points in Ceibal points to bow-and-arrow technology by the Terminal Classic period.

Skeletal remains excavated from the lowland Maya site of Ceibal, representing approximately 117 individuals, provide significant data for the study of changes in bodily treatments and mortuary practices from 1000 b.c. to a.d. 900. The early Middle Preclassic residents of Ceibal apparently did not bury their dead inside residential structures, which represents a burial practice different from those found at contemporaneous Belizean sites. During this time, tabular erect cranial deformations were found among possible local residents. Sacrificial burials were present by the end of this period, but skeletal remains of violent rituals deposited in public spaces increased from the Middle Preclassic to the Late Preclassic. During the Late Preclassic, tabular erect cranial deformations coexisted with tabular oblique shapes. The Classic period witnessed a prevalence of tabular oblique forms, which were probably tied to local residents. The common placement of the dead under house floors and the preference of ceramic vessels as burial goods also indicate Ceibal's strong affinities with other parts of the Maya lowlands during the Late Classic period. During the Terminal Classic period, there was a resurgence in the placement of sacrificial burials in public spaces and tabular erect cranial deformations were found in possible non-local individuals.

Our investigations at the lowland Maya center of Ceibal have demonstrated that a formal spatial pattern consisting of an E-Group assemblage and large platforms started around 1000 b.c. and gradually expanded over the next several centuries. A re-evaluation of ceramic and radiocarbon data from other lowland Maya sites suggests that the beginning of sedentary life and ceramic use in various parts of the Maya lowlands started roughly simultaneously around 1000 b.c., which may have been triggered by a change in maize productivity. The standardized spatial pattern including the E-Group assemblage probably developed in the Isthmian Interaction Sphere, encompassing the southern Gulf Coast, central Chiapas, the Chiapas-Guatemalan Pacific Coast, and Ceibal, during the transitional period between the decline of San Lorenzo and the rise of La Venta as a major center (1200–800 b.c.). Most of the lowland Maya communities adopted the E-Group assemblage after 800 b.c., but not other elements of the standardized spatial pattern.