Archaeological data as evidence of sustainable development: cases from the Gulf Coast of Mexico

Abstract

Traditional knowledge as a source of sustainable development is a research topic that generally falls in the realm of ethnology and social anthropology. Archaeology, on the other hand, can provide the longue durée perspective on past and sometimes lost traditions that may be significant as modern sustainable strategies. This paper presents archaeological cases of long-standing traditional knowledge in agriculture and construction in the humid tropical lowlands of the Mexican Gulf Coast, which were lost about ad 1000 through episodes of cultural conflict. The first case concerns the agricultural use of wetlands for the intensive production of commercial and subsistence crops (cotton and maize). The second case is monumental earthen architecture, including pyramids and palaces, apparently achieved by using petroleum derivatives as an earth stabilizer. Besides evidencing sustainable practices, archaeology also provides the economical and socio-political context in which such labor-intensive strategies evolved and thrived for centuries. This context analysis allows cost–benefit concerns to be approached, if the reintroduction of such alternative technologies were contemplated in a modern market-oriented world.

Keywords:

• pre-Columbian archaeology
• technology
• tradition
• earthen architecture
• intensive agriculture

Introduction

The interest in traditional knowledge as a source for sustainable development strategies has mainly come from ethnographic and historical evidence. Though such data may provide records spanning many centuries, particularly in some areas of the Old World, they are severely limited in their time scope in cultures where written records are scarce or do not concern themselves with technological knowledge and production records. This is a drawback, as sustainability is a topic in which the time factor is crucial to evaluate the viability of a certain practice. In these situations, archaeology can provide information on production strategies that were successfully applied for centuries, but were then abandoned either if they became unsustainable or were simply lost due to a variety of causes independent of the strategy itself, which may range from climatic change, internal upheavals, or foreign conquest. Archaeology is ideally suited as a science to approach the chronological lapse during which some strategies were applied, the ecological setting and the demographic conditions in which they were successful, the socio-political system that was needed to implement them, as well as the historical causes for their emergence and abandonment.

In this paper, I will address two types of strategies, one for agriculture and another for construction, which would now be considered unviable from our modern, occidental point of view. Yet archaeology proves that both were highly successful for several centuries, demonstrating their sustainable character in the humid tropical environment of the Gulf Coast of Mexico. Both strategies could be reintroduced in contemporary living, subject to changes imposed by modern standards and benefit expectations, as they have clear ecological advantages: the agricultural strategy allows the sustainable exploitation of seasonal wetlands, of high environmental value, while the construction strategy offers the possibility of building in raw earth in an adverse climate, thus providing an option for economical, bioclimatic, and low-energy housing in tropical regions that worldwide tend to be either on the low end of the development scale (where people cannot afford expensive construction), or on the very upper end, where human occupation becomes extremely energy consuming (due to refrigeration, air conditioning, isolation, and pest control requirements).

The archaeological cases described in this paper belong to the Central Veracruz Classic period culture area, best known for its superb sculptures in clay, like the Smiling Faces, and in stone, like the so-called Yokes, Hachas and Palmas, which are part of the paraphernalia used in the decapitation ritual associated with the traditional hip ball game that functioned in this area as a state religion during the first millennium ad (Daneels, 2012) (Figure 1). During this period, small-scale state-level societies dotted the central Gulf lowlands, with a settlement hierarchy in which high-ranking centers had major architectural compounds with pyramids, ball courts, and palaces surrounding large plazas, the best-known site being El Tajín. In the study area, a 1200 km² area of the lower Cotaxtla River basin, immediately south of the city of Veracruz, sites of all ranks were of earth, and the population reached its maximum around ad 500–700, settling in all available ecological niches, including the seasonal wetlands that had been until then only sparsely occupied (Daneels, 2008) (Figure 2). While the large population explained the workforce available for building monumental architecture, it required feeding and providing with basic tools for cooking and cutting, for which the stone could only be obtained through long-distance exchange networks.

Figure 1. Diagnostic elements of the Classic period Central Veracruz Culture: (a) Smiling Face figure (only in South Central Veracruz), and elements related to the decapitation ritual and ball game paraphernalia; (b) Vega de Aparicio stela; (c) hacha with interlaced scroll pattern; (d) plain yoke (Photo credits: (a) code 03250 1/4; (b) code 00337-1; (c) code 0086-2; (d) code 00488-1, reproduced with permission 068/2015 of the Museo de Antropología de Xalapa, de la Universidad Veracruzana).

Figure 2. Lower Cotaxtla basin 1200 km² survey area, indicating the settlement hierarchy, and the intensive agriculture areas mentioned in the text (1, Primero de la Palma, in the saline plains; 2, Buenavista; and 3–5, other raised field complexes) (Image credit: Annick Daneels, 2015). Inset showing sites mentioned in the text and the location of the study area in State of Veracruz (white outline) of the Gulf Coast of Mexico (Image credit: country and state contour lines based on INEGI 1992 Geographical map 1:4,000,000).

Intensive agriculture in seasonal wetlands

The first series of cases concern the identification of two strategies for intensifying agriculture in seasonal wetland areas, both of brackish and sweet water. This is interesting, for in the view of the new international awareness of the importance of conserving wetlands, instead of drying them out (RAMSAR, 1994), these strategies would offer the possibility of economically exploiting wetlands while respecting their ecological nature (Barbier, Acreman, & Knowler, 1997). The archaeological and botanical data presented below have been previously published in detail (Daneels, Flores, Ibarra, & Zolá, 2006), and will only be summarized here for the purpose of the argument.

Conventional occidental wisdom and anthropological theory would consider such strategies unviable or simply impossible. In the theoretical framework of Cultural Ecology, the humid tropical lowlands were for a long time considered as an environment dependent on slash-and-burn agriculture, which forced the farmers to live spread out over large areas, impeding population growth and concentration that could allow the development of greater social complexity leading to the formation of states; in these ecological and socio-cultural conditions, agricultural intensification was deemed impossible (Sanders, 1971; Sanders & Killion, 1992).

Present-day use of these seasonal wetlands, derived from Colonial period practices introduced by the Spaniards after the conquest of Mexico, is oriented towards dry-season cattle ranching, providing few benefits, particularly in the case of the brackish water wetlands. In the latter, additional, though illegal, earnings are obtained through hunting blue land crab (Cardosoma guanhumi) and extracting timber of mangrove (mostly Avicennia germinans). The areas in the immediate surroundings of major cities, as is the case of the first archaeological site discussed, are rapidly being in-filled for urbanization, efficiently killing off the remaining ecosystem that years of poaching had barely affected.

The brackish water wetland case

The Primero de la Palma site was part of the expansion area of a regional capital, La Joya, that along with several others arose along the fertile alluvial terraces of the major rivers, the Jamapa and the Cotaxtla, during the Protoclassic period (100 bc–ad 100). When the population in the La Joya entity grew after ad 500, it expanded towards the coast, settling around small third-rank administrative centers on the brackish water seasonal wetlands behind the mangrove belt. This spread seemed at first surprising, in view of the low agricultural productivity of such areas today, and the absence of evidence of exploitation of palustrine and coastal resources, like oyster, shell, crab, or fish.

The first inkling of the use of the wetlands came from the surface survey results, when the Joya entity (120 km²) was shown to have more than 30% of all spindle whorls in the 1200 km² study area, most of those from the wetland sites. This led to the hypothesis that cotton may have been cultivated on those floodplains, as it is a plant native to the tropical coast and resistant to saline environments (Sauer, 1967). Excavations revealed that the mounds were built on a barely emerged floodplain, with incipient soil formation. Coring along three transect lines crossing from alluvial levees to the mangrove belt showed organic soil enrichment at the level of pre-Columbian occupation, preceded and followed by the water deposited gley sediments. The botanical analysis of the samples showed sturdy halophylic and hydrophilic grass communities (Euphorbiaceae and Equisetaceae) normal for brackish water floodplains predominating in the levels prior and posterior to the archaeological settlement, while the paleosoil contemporary to the mounds consistently held significant amounts of charcoal and weeds that accompany the practice of slash-and-burn agriculture (of the Chenopodiae, Poligonaceae, Compositae, and Amaranthaceae families, as well as Malvaceae, though not of the Gossypium genus). No evidence of cultigens showed up in the samples, but this is to be expected if as surmised the crop sown on these plains was cotton: the seeds are picked when harvesting the cotton ball, making it unlikely to find them in the soil samples. An experiment started in June 1999, sowing three Gossypium hirsutum seedlings, the Mexican cotton variety obtained from local gardens, in the floodplain adjoining a mound; these started growing and reproducing without human intervention (apart from erecting a cattle fence around them), in spite of repeated seasonal flooding (Figure 3). Biologists participating in the experiment were skeptical of success due to the compact quality of the gleysoil, but observation showed that it was the active crab burrows that provided the roots the oxygenation necessary for growth, demonstrating the symbiosis between natural fauna and induced crop.

Figure 3. Cotton growing experiment in Primero de la Palma: (a) June 1999; (b) August 2001; (c) September 2003 (Photo credits: (a) (b) Annick Daneels; (c) Carlos Dávila).

The sweet water wetland case

The Buenavista site was located immediately adjacent to another local capital, La Tasajera. It consists of an insilted lagoon between two minor tributaries of the Cotaxtla River, still occasionally flooded when this major river grows in excess during the rainy season. A 1980 aerial photograph showed a reticulated pattern characteristic of raised fields along the Gulf Coast of Mexico (Siemens, 1989), leading to investigating the area for agricultural evidence (Figure 4). Microtopographical mapping showed a complex hydraulic system making use of a small spring to the east to circulate water through the canal system, including a major collector canal to direct the runoff water towards the main tributary to the west, and overflow canals on the surrounding levees to drain the fields in case of river flooding; excavations indicated that some time about ad 500 humans started digging canals in what was a waterlogged marsh, using the mud to build raised fields; palynological residues showed evidence of maize cropping, associated again with weed growth and charcoal from the seasonal burning of harvested stalks, a traditional fertilizing strategy (Daneels et al., 2006). Although the surface of the raised field complex is quite small (about 10 ha), compared to other field complexes in the region that may cover several square kilometers (Heimo, Siemens, & Hebda, 2004; Siemens, 1989; Wilkerson, 1997; Figure 2), the possibility of obtaining two to three crops a year makes it a highly productive strategy.

Figure 4. View of raised fields from Buenavista (Image credit: Annick Daneels, 2000).

The socio-political context of intensive agriculture in wetlands

Both cases date from the Classic period, when population density reached an all-time high. Both strategies are labor intensive, and could not have arisen without the existence of state-level organization to plan, build, and maintain them. In the brackish wetland, the intensification concerns a cash crop, as cotton until the Postclassical period was used as a standard barter item. The saline wetlands in the territory of the La Joya capital totals 40 km², on both sides of the river, providing an annual crop way beyond the needs of the local population, estimated between a minimum of 15,000 and a maximum of 40,000 persons, in 120 km² (Figure 2). The presence of third-rank centers of the administrative type suggests that the production was ordered and controlled by the capital, and used for long-distance commerce, for the acquisition of stone like obsidian (for cutting blades) and basalt (for grinding stones). In the case of the raised fields, the survey showed they are spatially closely linked to capitals of territories arising at a later stage of settlement and situated in the less fertile hilly soils. As the dispersed population of these territories was able to produce for its own subsistence, but not enough for surplus, an alternative mode of production was required to feed the inhabitants of the capitals, which ranged in the order of 1000 persons per square kilometer, an urban density. Thus, it is probable that the governors planned and controlled the design and exploitation of the raised fields, in order to obtain the main subsistence crop for the urban population. The end of both practices correlates with the arrival, around ad 1000, of foreign people from the highlands, with different agricultural traditions: they preferred high ground, with well-drained soils, clustering on the alluvial terrace. Though historical evidence of tribute lists shows that the region, in the Late Postclassic part of the Cotaxtla province in the Aztec empire, was a major cotton producer, there is no evidence that the brackish wetlands were still used for cropping. This could also be related to increased rainfall after ad 1000 (Sluyter & Domínguez, 2006, p. 1149), making cultivation impossible in permanently waterlogged areas (though resistant to occasional flooding, cotton is not a hydrophilic species).

Thus, the cases show evidence of at least 500 years of success in agricultural intensification for the production of commercial and subsistence crops, without changing the essential ecology of the wetlands. The abandonment of both was related to factors independent of the strategies themselves: cultural conquest and possibly climatic changes, indicating that they did not lose sustainability.

Earthen architecture in tropical lowlands

The second strategy is that of building in raw earth. Though very common worldwide, as the United Nations estimates that one-third to half of the world's population live in buildings made in part or wholly of earth (Libaert, 1985, pp. 3, 63), it is commonly associated with arid and semi-arid climates, because water is probably the major cause of its deterioration. Thus, the presence of a strong, millenary tradition of earthen architecture in the tropical lowlands of Mexico is surprising, again from the point of view of modern, occidental knowledge.

Vernacular versus monumental architecture

When approaching earthen architecture (or any architecture) it is important to differentiate between vernacular, domestic building and monumental architecture. The first is rooted in family and community needs, values, and labor force, transmitted through centuries of oral tradition with little modification; thus, ethnographic evidence of the last century is often a truthful guide to understanding its principles and techniques.

Vernacular architecture is perfectly viable, but will not have a long life after abandonment, as it is dependent on continuous maintenance. In the case of the mounds which supported low-rank dwellings in the wetlands, interesting strategies were developed to avoid the rise of capillary humidity, a bane in such environments. Though effective, they seem to be ad hoc solutions, making screening layers under the floor level that can consist of a bed of oyster shells, or a course of round clay balls or of hourglass-shaped necks of ceramic jars. The buildings themselves were made of wattle and daub with palm-thatch roofs, much like the traditional houses today.

The monumental architecture is at a different level: it requires a specialized knowledge to resolve the engineering problems of size, and a level of organization capable of coordinating a large workforce for building and maintenance, and resolving the logistic problems this involves (how to feed the workforce, obtain the building materials, plan the sequence, etc.). Such expert knowledge is necessary to achieve durable constructions for public, administrative, and ritual use. It is this knowledge that is considered relevant for the purpose of this paper, as it represents a better option for reintroduction according to modern building standards and comfort expectations.

Monumental earthen architecture tradition

The definition of a Mesoamerican earthen architecture tradition is a recent one. For a long time, the large mounds that characterize the archaeological sites of the central and southern Gulf and Isthmian lowlands were perceived as just that: large heaps of earth used as platforms for wattle-and-daub buildings, similar to the Mississippian Mound-builders or the Amazonian jungle cities (though the latter are now also being reevaluated in terms of their socio-political relevance, see Baltus & Baires, 2012; Heckenberger, 2009).

The earliest evidence of standard Mesoamerican construction types built in earth in the lowlands include: ball courts and elite residences (1600 bc, in Paso de la Amada, Chiapas: Hill & Clark, 2001), sunken patio groups (1200 bc, in San Lorenzo, Veracruz: Cyphers, Hernández Portilla, Varela Gómez, & Gregor López, 2006), and pyramid-plaza groups (900 bc, in La Venta, Tabasco: Gillespie, 2008),¹ the latter two cases pertaining to the Olmec culture (Figure 2, inset). These were excavated by test trenches and systematically reburied, limiting the in-depth research of the building technology. The majority of earthen sites that dot the Gulf Coast are often only defined through surface survey, and none have been restored.² In these circumstances, recent research at the heavily damaged Classic period site of La Joya provided a unique opportunity to understand the building sequence and the construction systems, and to obtain abundant building samples for mineralogical and chemical analyses. The results showed the existence of a sophisticated architectural knowledge in resolving the problems of building in earth in environments with annual rainfall between 1000 and 3500 mm. The site is part of a culture that emerged in the Classic period from roots in the Olmec culture, showing that the tradition of monumental building in earth on the Gulf Coast evolved and endured for more than 2000 years, certainly a significant indicator of sustainability.

The building techniques

Building in earth is different from building in stone or brick, as it is much more dependent on the quality of the available sediment, especially the type of clays and the morphology of sands, and on the environment, with wide variations in temperature or humidity being especially detrimental. La Joya, as much of the Gulf lowlands, in these aspects represents a worst-case scenario: a predominance of expansive clays and violent rainstorms in the summer alternating with strong dry windy periods in the winter. As the monumental compound consisted of buildings erected on elevated platforms placed around large plaza expanses, the construction techniques aimed to control the clay's expansion–contraction cycles, and at protecting the surfaces from rain damage. The specific archaeological and technological details have also been published previously (Daneels & Guerrero, 2011; Kita, Daneels, & Romo de Vivar, in press), and will only be summarized here.

To control the fill pressure in the large basal platforms a checkerboard pattern of alternating clay cubes and sand cubes was used. Surface drainage was achieved by sloping the surfaces, gathering runoff to subsurface drains made of terracotta clay pipe modules fitted into each other, emptying in large reservoirs surrounding the site, which protected it from river flooding. Surface resistance to rainfall was obtained using very clayey facings, stabilized with a petroleum-derived substance, from light fractions of crude available from natural seeps along the Gulf Coast. The same substance was added to the adobes used to build the actual precincts and rooms, to make them resistant to capillary humidity. The result was an architecture as imposing as other Mesoamerican cities of stone, with pyramids, palaces, altars, and ball courts, stretching the first millennium ad (Figure 5).

Figure 5. 3D reconstructions based on archaeological evidence of the central area of the La Joya site: (a) Pyramid and North Platform-palace circa ad 200; (b) Residence on the East Platform-palace circa ad 450; (c) site circa ad 700, viewed from across the eastern water reservoir; (d) view from site, circa ad 700: ball court to the south of the pyramid, reservoirs shown in black (Image credits: a, c, d, David Piña, 2014; b, Giovanna Liberotti, 2013).

The socio-political context of monumental architecture

The cases cited, from the Olmec period as well as the Classic period, arise in a context of complex societies (Pool, 2007). Stratified societies, with probably hereditary leaders capable of drawing a large labor force in the name of ideological values, were able to create artificially built centers for administrative and ritual purposes. These centers served as the physical and symbolical points of reference both for the surrounding, urbanized population, as well as a hierarchy of subordinate centers in the capital's territory, that replicated the architectural layouts at a scale smaller both in volume and in functional attributes, controlling the rural population.

From this paper's point of view, the interesting fact is that most sites have several building stages. In the case of La Joya it was possible to ascertain that these reconstructions spanning the first millennium ad (two in the case of the pyramid, six in the case of the palaces) responded to changes in the political program, not to a deterioration in the state of the buildings. At the end of its building history, the site had a volume of 144,478.3 m³ in constructions above the plaza level, though the fills to achieve the elevation of the basal platform of the site 2 m above the surrounding alluvial terrace added about 200,000 m³ to this figure, the total corresponding to 620,000 tons of earth, a major labor input even if spread over four major rebuilding programs, occurring about every 250 years, but also a striking testimony to the effectiveness of the building technology.

Recurrently finding a petroleum derivative as part of the mud mix in the archaeological building samples was unexpected, though since the nineteenth century asphalt emulsions have been used to stabilize adobes for modern construction as well as earthen taluses in civil engineering projects (Hall, Najim, & Keikahaei, 2012). As there are abundant natural seeps along the Gulf Coast, petroleum products were available and thick asphaltic mixes are known to have been used there since the Olmec period for canoe caulking and waterproofing (Wendt & Cyphers, 2008). However, in the case of the La Joya samples, the substance was not asphalt but a light fraction of crude, so its use would represent a technique different from the modern one. Research and experimental reconstruction of this pre-Columbian technique is ongoing.

Alternatives for modern use

Both pre-Columbian strategies open up alternatives for modern use. For their reintroduction to be viable, it is necessary to take into account modern norms, technology, and benefit expectations. I will in the following paragraphs make reflections and suggestions on how these strategies could be interesting for our modern world, though as I'm an archaeologist, not an economist, I do not pretend that they are more than just simple reflections. Nevertheless, these may awaken interest from stakeholders in the development of sustainable strategies for agriculture and housing in tropical climates.

About the use of saline plains for cotton growing, the main drawback from a modern point of view would be the limitation in the use of mechanical cotton harvesters during the rainy season. Though the State of Veracruz was an important cotton grower in the eighteenth and nineteenth century, production in the central area stopped after a brief attempt at revival in 1950–80 (Chávez Orozco, 1965). Actually, cotton growing in Veracruz has become a minor activity (INEGI, 2013). Yet since the late twentieth century, interest has arisen in pharmaceutical research on the properties of gossypol from the cotton seeds (for recent examples, see Mehrpour, Codogno, & Chen, 2009; Volate et al., 2010), while on the other hand, economically viable small-scale textile production has been attained by commercializing high-quality hand-made clothing applying traditional spinning, dying, and weaving techniques, as in the case of the Sna Jolobil cooperative of Tzotzil and Tzeltal Maya women in the State of Chiapas in Mexico. Thus, if researchers interested in careful growing of special cotton plants for pharmaceutical purposes could get the attention they need from groups interested in traditional ways of cropping and textile production, this combined interest could warrant the labor investment required for an approach with a low mechanical/chemical input.

The use of raised fields in the sweet water wetlands for high yields could also be implemented from the current interest in organic food production, wherever the local water sources used for this type of agriculture are (still) of good quality. On the other hand, the actual use of these areas as dry-season cattle pasture is still a viable option, especially if the current ranchers were made aware of the benefits of switching to organic label quality product standards and assisted to commercialize their products (either diary or meat) as such.

Finally, in the case of earthen construction, there has been a surge in worldwide interest since the 1970s because of its bioclimatic, economical, and sustainable qualities. This effort is now led by institutions like the United Nations: HABITAT (since the 1980s), the UNESCO Chair in Earthen Architecture at CRATerre in France (since 1998, with representatives in Germany, India, Korea, etc.), and the World Heritage Earthen Architecture Programme (since 2007). In close collaboration with the ICOMOS (International Council on Monuments and Sites), host of the International Conferences on Earthen Architecture since 1972, the ICCROM (International Centre for the Study of the Preservation and Restoration of Cultural Property) in Rome and the CRAterre in Grenoble started with the Gaia project (1989–98), which expanded as the TERRA project (1997–2005) with the inclusion of the Getty Conservation Institute (Avrami, Guillaud, & Hardy, 2008). These endeavors promote both the preservation of existing heritage and the application of earthen construction in the modern world. They have impacted on a large scale, as evidenced by the recent Laufen Manifesto for a Humane Design Culture (2013, http://laufenmanifesto.org/).

Interestingly, though these projects involve many archaeological sites, most of the intervention or construction methods, based on the use of traditional, “authentic”, techniques are derived from direct ethnographic knowledge (Correia, Dipasquale, & Mecca, 2014). At least in the case of earthen architecture,³ very little effort has been made to study and understand the technology developed by ancient cultures, possibly under the (erroneous) assumption that if the technology were sustainable, it would have survived to this day, and that current traditions would reflect the entirety of the ancient knowledge. As argued above, this is not necessarily the case. It's like assuming that if you can build your house, you can also build a skyscraper. The latter requires architects and engineers, a higher quality of building materials, a more exacting building technology, in short a level of specialized knowledge and access to resources that the normal housebuilder does not have (or need). Higher level technological knowledge may become lost when the tradition of monumental architecture is interrupted, for example, through cultural replacement through conquest (as in the case of the central Gulf Coast of Mexico), through the adoption of new building modes (as in the case of Mesopotamia), through the abandonment of the area (as in the case of the Harappa culture). Thus, it is important to dedicate more time to thoroughly understanding the ancient techniques of monumental architecture that achieved spectacular successes as the result of centuries of experimentation and state-sponsored building, to the point of still being worthy of admiration today, like the 150 sites of earth acknowledged on the UNESCO's World Heritage List (Joffroy, 2012).

In the case of La Joya, presented in this paper, the building systems revealed the design of original strategies adapted to the local building materials and the requirements of durability and monumentality, in a very adverse environment. A major contribution to modern building would be the reconstruction of the stabilizing procedure, a work in progress.

Closing words

This paper set out to show how archaeology could provide useful information on the topic of traditional knowledge and sustainable development. Yet it is rarely part of the mainstream papers on the topic, its contributions being more widely recognized in the aspects of tangible heritage conservation and sustainable cultural tourism. For one, the dynamic of archaeological research is slow: extensive surveys, painstakingly precise excavations, long periods of analysis on evidence that has degraded through time, the absence of historical writings to corroborate interpretations, all make for a cautious and tardy production of results. In the frantic search for solutions by political programs and business enterprises, archaeology is desperately slow. Secondly, archaeologists do tend to publish in the academic field of humanities, rarely if ever venturing into the realm of applied science. Thus, this paper is a call to both archaeologists as well as stakeholders in sustainable development to reach out and listen to each other. Something good may come of it.

Acknowledgements

The archaeological data presented in this paper were obtained in my capacity as researcher of the Institute of Anthropological Research of the National Autonomous University of Mexico (UNAM), during several field seasons of the project “Exploraciones en el Centro de Veracruz”, with the permission of the Mexican Council of Archaeology of the Instituto Nacional de Antropología e Historia (INAH). Giovanna Liberotti and David Piña created the 3D reconstructions of the La Joya site while participating in the project between 2012 and 2014.

Disclosure statement

No potential conflict of interest was reported by the author.

Funding

This work was supported by Mexico's Consejo Nacional de Ciencia y Tecnología (CONACyT) [individual grant 27793 H (1999–2000)]; Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica of the Dirección General de Asuntos del Personal Académico (DGAPA) of the National Autonomous University of Mexico [grant IN300812 (2012–14)].

Notes

1 All dates in this paper are expressed in uncalibrated radiocarbon years.

2 Only at Zapotal was a small shrine preserved and roofed over, for public viewing (Wyllie, 2010). However, it is only a small part of a large platform, itself part of a monumental pyramid-plaza compound. Some buildings were unearthed as part of salvage excavations, but the data are only available in several unpublished thesis or technical reports.

3 This is not the case for wood construction, for which many technical and structural studies exist, particularly in Europe and Asia, based on historical data and monuments.