The type of urbanism that flourished principally during the Late Formative through Classic period in the Gulf Lowlands can be characterized as a distributed network of civic-ceremonial nodes that served an expansive, low-density population. Tropical areas of the world where critical resources, like water and good soils for agriculture, are ubiquitous do not tend to lead to the dense nucleated cities that developed in semi-arid regions like Mesopotamia, highland Mexico, or the Indus Valley. Rather than nucleated settlements, dispersed populations spread out among their agricultural fields with patterns of social and political interaction focused on monumental epicenters, or nodes, situated among them. Rather than live full time in cities with direct access to the services that those centers provide, residents habitually come into monumental centers for ritual, markets, and to coordinate projects, such as raised field agriculture. The monumental centers still provided services to the people living in a region, which is why I consider this to be a pattern or center/hinterland interaction following a functional definition of cities. However, there is no discreet unit that could be called "city" in contrast to a rural countryside. Urban and rural blend together. 

Since 2015, I have been involved (with Barbara Stark) in creating a database of architecture in the southern half of Veracruz to analyze patterns in the distribution of different styles of architecture. The polities that formed in this region were not isolated or independent city states, like we see in many other parts of the world. Nor were they integrated hierarchically under one powerful center, with some possible and temporary exceptions. However, the extremely high degree of architectural similarity among the configurations of public plaza groups implies peer interactions among hundreds of settlement segments that spanned areas of thousands of square kilometers. In south-central Veracruz, residents constructed standard plan plaza groups that followed one architectural grammar, and in southern Veracruz groups followed a similar but slightly different grammar. The figure below summarizes these differences.  

By modeling these architectural attributes across space we can highlight nuances in the social networks and boundaries that operated during Classic period Veracruz. Zones with continuous replication of similar architectural plans were likely interlinked by social relations (marriage) and economic exchanges, where as an abrupt geographic shift from one plan to another might indicate low levels of interaction or intentional maintenance of a social boundary, such as the transition zone highlighted in the map below along the Upper Papaloapan Drainage, and the Southeastern Tuxtla Mountains based on the positioning of ballcourts. 

I am currently pursuing the application of social network analysis to understand how these patterns formed and spread across the landscape, with the intent to identify features of the network that might help to explain the longevity of settlement in the region (over 1000 years of growth) and the sudden cessation of this pattern around 800-900 AD.