Ceremonial architecture of late precontact (A.D. 600-1500) societies of Puerto Rico consists of stone-lined plazas and ball courts (bateys,). Archaeologists use these structures to signify the onset of hierarchical “chiefly” polities and to interpret their regional organization. Problematically, little consideration is given to the costs of their physical construction and the associated organizational implications at local and regional scales. In this paper, we use data gathered through geoarchaeological field investigations to develop labor estimates for the plaza and bateys at the site of Tibes—one of the largest precolumbian ceremonial centers in Puerto Rico. The estimates provide a basis for addressing how these features were constructed at the site and are considered within the broader organizational contexts of incipient polities in the island's south-central region between A.D. 600 and A.D. 1200.

This study places the recently excavated ninth-century A.D. four-part calendrical notations at Xultun (Lunar Table, Ring Number, Long Count, and Multiplication Table) in the context of both Classic monumental inscriptions and astronomical knowledge in the Postclassic Dresden Codex. We demonstrate that the Lunar Table employed a formula attributed to Palenque and that it could have been used as a device to determine precisely where to break the sequence of alternating 29- and 30-day months one finds on dated monuments. All four categories found at Xultun appear in the Dresden Codex. The Ring Number, which bridges a date in the deep past with one in the recently completed era, is a perfect fit with one of the most fundamental Dresden eclipse cycles. Our analysis of glyphs accompanying the Long Count date enables us to place candidate eclipses, especially one that corresponds with a conjunction of Mars, in real time. We argue that the large multiples were extracted from, or prepared for, warning tables like the Dresden eclipse table, and we demonstrate why such tables must have existed well before the Xultun inscriptions. Thus, while the writings in the Dresden manuscript constitute a finished product, the writing on the wall of residential Structure 10K-2 is more akin to what one might find in an astronomer's notebook.

Despite a long history of research, interactions between the Tiwanaku polity of the Andean Middle Horizon (ca.A.D. 500-1100) and the San Pedro de Atacama oases of northern Chile remain controversial. Here, we investigate Middle Horizon interactions through an isotopic identification of the geographic origins of individuals buried in San Pedro de Atacama cemeteries and present the largest radiogenic strontium isotope dataset generated, to date, for the Andes. For individuals in Middle Horizon San Pedro de Atacama cemeteries ofCasa Parroquial, Coyo Oriental, Coyo-3, Larache, Quitor-5, Solcor-3, Solcor Plaza, Solor-3, and Tchecar Túmulo Sur, mean tooth enamel and bone 87Sr/86Sr = .70834 ± .00172 (2σ, n = 273). Overall, the mean 87Sr/86Sr values from Middle Horizon San Pedro de Atacama cemeteries support the idea that interactions between Atacameños and inhabitants of other regions varied by ayllu, an Andean kin-based community structure, with some ayllus incorporating individuals with a wider variety of geographic origins than others. When our interpretations of the radiogenic strontium isotope data are contextualized with analyses of mortuary behavior and recent biodistance analyses, we argue that the San Pedro de Atacama oases appear to be have been inhabited by culturally and biologically diverse groups, rather than by large numbers of colonists from the Tiwanaku capital and the Lake Titicaca Basin.

Khipus are knotted-string devices that were used in the Inka Empire for communication and for recording information. We recently analyzed the names and associated khipu cords in a newly discovered hybrid khipul alphabetic text from the Central Andes. Results indicate a significant relationship in the text between knot direction and a form of social organization known as moieties, in which S-knots correspond to the upper (Hanan) moiety and Z-knots correspond to the lower (Urin) moiety. This relationship suggests that knot direction was used to indicate moiety in Andean khipus and, as such, may represent the first decipherment of a structural element in khipus since the decoding of the number system in the 1920s.

In the Maya region scholars have long noted the connection between solar alignments and radial pyramids at sites such as Chickén Itzá, Dzibilchaltún, and Uaxactún. Just. 26.5 km west-southwest of Chichén Itzá, the site of Ikil also contains a massive radial pyramid, known as Structure 1. In May 2011 investigations at Ikil revealed that this pyramid also figures in a solar hierophany-the sunrise over the pyramid's summit on the days of the solar zenith transit. What is unique, however, is that the observation point for this event is situated inside of a cave to the west of the pyramid. In this paper, evidence is presented that suggests the location of Structure 1 was dictated by the orientation of the cave, and that the physical and ceremonial linkage of these two landscape features created the cosmic hub of Ikil. Furthermore, it is argued that ceremonies marking the solar zenith-a day largely ignored in Euro-Christian calendars-would have been enacted by the ruling class as a way to formalize and sanctify the annual rebirth of the agricultural cycle, while publicly displaying their connection to the divine and thus legitimizing their position of high religious and social status.

The research reported in this article explores Wari imperial strategies in the upper Nasca Valley of south-central Peru and, building on previous research, documents the flexibility and diversity of those strategies. The focus of these investigations is the site of Pataraya, a small Wari provincial outpost, and its environs. Despite its size, the rectangular enclosure at Pataraya is well planned and conforms to the canons of Wari state architecture documented at other Wari provincial sites. The site was founded early in the Middle Horizon (A.D. 650-1000) and then abandoned during the collapse of the Wari system. Extensive excavation at this condensed version of the Wari building tradition—over 60 percent—uncovered a pattern of spatially segregated use and access within the enclosure. Activities were relegated to specific patio groups with little replication of function, and the sectors themselves were connected by an astonishingly complex system of narrow corridors. The site appears to have been involved in the transfer of coastal products, especially cotton, to the sierra along an ancient road that is also associated with another much larger Wari compound and with the reorganization of an older local site near modern-day Uchuymarca, both of which were also documented during the project.