developments at Kaminaljuyu and their belief that Kaminaljuyu was primordial for its cultural and social innovations. Since their work, investigations chiefly undertaken by scholars from the New World Archaeological Foundation on the southern Pacific coast of Mexico have greatly altered this view, deepening in time the incipience of complex social and cultural events in Mesoamerica. Cultures of this phase had a stable agricultural community organized probably as a simple chiefdom. Over many years Shook and Kidder developed the Kaminaljuyu ceramic sequence, and it remains, with refinements by Shook and Marion Popenoe de Hatch, one of the most secure and reliable ceramic chronologies in Mesoamerica, although some doubts remain about the absolute dates due to a paucity of radiocarbon anchors (a revision by Inomata, et al. to the following chronology, based on Bayesian analysis, would push forward the ceramic phases by as much as 300 years, setting the Miraflores apogee to a 100 BC – AD 100 time frame). With Inomata, et al's revision in mind, the first significant settlement dates to the Arévalo phase, c. 900–800 BC, with indications of dense populations no later than c. 400 BC. By the end of the Las Charcas culture (800–350 BC), Kaminaljuyu was developing "religious and civic institutions." Scattered Las Charcas remains throughout the Valley of Guatemala mark a major occupation of the area at sites such as El Naranjo; at this latter site, as well as at El Portón some 50 kilometers to the north and Takalik Abaj, about 130 kilometers to the west in the lower piedmont, plain uncarved upright shaft stones called stelae, mark the first appearance of a cult of time-reckoning and which became one of the bases for the institution of Maya kingship. The architecture of Middle Preclassic structures consisted of hardened adobe bricks that served, later, as foundations for raised platforms and pyramidal temples. Excavations indicate that from early in the Middle Preclassic the community was large enough to produce heavy refuse deposits. Cotton was grown as well as maize; palaeobotanical research also has identified annonas, avocados, cacao, black beans, palm nuts, plums, and sapodilla (zapote blanco). Arboriculture developed – with groves of crop trees grown in terraces down to the edges of great ravines. Specialists practiced loom-weaving and were expert potters. Large-scale workshops for obsidian tool-making were spread around the ancient city. Religious practices that would later be further developed throughout Mesoamerica were elaborating during the