—  PALEOPATHOLOGY CLUB   —

Paleopathology of the Ancient Maya at Tikal, Guatemala


Lori E. Wright
Texas A&M University
College Station, TX


The city of Tikal was one of the largest urban communities of the ancient Maya, and was occupied from 900 BC to AD 950. Located in the center of the Guatemalan Department of Peten, Tikal is surrounded by lush high subtropical forest. Excavated by the University of Pennsylvania in the 1950's, and by the Guatemalan Proyecto Nacional in the 1980's, Tikal is now the center of a large national park, and is the country's most visited tourist site. At its height around AD 700, the city had a population of 62,000 persons [1]. Excavations have documented the growth of the city center, which is dominated by large temple and palace complexes, as well as the surrounding settlement. Studies of architectural variation among domestic ruins at the city have shed light on the broad range of social status groups that occupied the city, and have helped to reconstruct ancient Maya society as a hierarchically stratified society.

Because of Tikal's large urban population, the site has been the focus of hypotheses about the implications of high population density, and the demands of a maize-dominated agricultural system on the fragile tropical forest environment. A prevailing explanation for the collapse of Classic period Maya civilization around AD 800 is that overpopulation led to agricultural stress and environmental deterioration, causing the collapse of food production systems. Support for this model was published in a classic paper examining skeletal stature at Tikal. Haviland [2] described a decline in male stature from Early Classic (AD 250-600) to Late Classic periods (AD 600-900), as well as a taller stature for males buried in elaborate tombs than for males buried in simpler graves.

This paper presents preliminary results of recent paleopathological research on the health of the ancient Maya at Tikal. I collected macroscopic data on bony and dental lesions for skeletons excavated by both the Penn and Guatemalan excavations. A few radiographs were taken of select pathological specimens. Although a large number of burials have been excavated at Tikal, many of the remains are very poorly preserved, and a large number of the skeletons excavated by the University of Pennsylvania are no longer curated. Statistical analyses of the data is still ongoing, however, some preliminary observations are possible at this time. The research aims to test hypotheses about the nature of diet and health change at the city over time and among social groups.

Following from Haviland's early work at Tikal [2], we studied skeletal stature to assess growth among social groups and over time. At Tikal, skeletal remains are very fragmentary, thus we approached this aspect of the project by first developing regression equations to estimate the length of fragmentary long bones using a comparative forensic sample of modern Maya skeletons from Guatemala [3]. Even so, the number of skeletons from Tikal for which we were able to reconstruct stature is small – just 33. Although the sample does not reveal chronological changes in stature, perhaps because of its small size, an interesting pattern is evident in the degree of sexual dimorphism among social groups. Contrary to Haviland's findings, we observed a significant relationship between female stature and the architectural context in which skeletons were buried. Although male stature is comparable among diverse social contexts, females in small domestic groups are substantially shorter than those buried in larger "intermediate" groups with vaulted stone architecture [4].

Childhood growth can also be studied using defects in the teeth. Dental enamel hypoplasias —small depressed grooves across the tooth— form during childhood as a result of episodic illness due to both malnutrition and infection. By studying teeth throughout the dentition, we can gauge the stress experience of children during growth. Enamel hypoplasias are quite common on Tikal dentitions, with a maximum frequency of 88.5% of mandibular canines and 86.5% of maxillary canines showing the defects. Preliminary statistical analyses of a subsample of the skeletal series show few changes in the abundance of the lesions over time. Only the first permanent mandibular molar shows a significant difference over time, with fewer teeth affected in the Late Classic period than during the Early Classic. The maxillary first molar also shows fewer defects in the Early Classic period, albeit not statistically significant. This suggests little change in childhood stress experience over time, with a possibly later age of peak incidence during the Late Classic that resulted in fewer defects on the first molar, which mineralizes between birth and 3 years of age.

Several specific maladies can be seen in the remains from Tikal. Cranial lesions caused by anemia are common on the skulls of Tikal children, and on some adults, who survived the childhood illness, but bear its scars. Bony infection is also evident on a number of longbones, however, surface erosion of the bones hinders a systematic study of the frequency of bony infection. This paper will also describe four skeletons with unusual lesions, that merit a more extended differential diagnosis. Two of these skeletons show bony growths in the mandibular body. Although it is not possible to come to a definite identification without destructive histological analysis, both appear to be benign slow-growing tumours. One is most consistent with a hyperplasia, osteoma or osteoblastoma, while the other might be an odontogenic tumor, an osteoma, an osteoblastoma, or a fibro-osseous lesion. A young adult skeleton from an Early Classic multiple burial suffered from bilateral congenital club foot. Diane France assisted by making casts of the bones, and the cast tarsals and metatarsals were rearticulated to study the specific anatomy of the deformations. One elderly female skeleton shows a severe case of osteoporosis, that resulted in flattened parietal bosses. Although this cranial deformity is sometimes described as a congenital defect, its presence in this elderly female is consistent with a diagnosis of osteoporosis. However, this is a surprising finding given that the Maya at Tikal consumed very high levels of calcium, obtained from maize that was prepared by soaking it in a calcium carbonate solution.

In general, the pathologies seen at Tikal are similar to those found in most ancient Maya cities. Although Tikal's population was larger than many Maya communities, it's inhabitants do not appear to have suffered from dramatically higher disease loads. Preliminary analyses show some social patterning in childhood growth status, however, statistical analysis of the data is still underway.

References

  1. Culbert, T. P., L. J. Kosakowsky, et al. (1990). The population of Tikal, Guatemala. Precolumbian Population History in the Maya Lowlands. T. P. Culbert and D. S. Rice. Albuquerque, University of New Mexico Press, pp. 103-121.

  2. Haviland, W. A. (1967). Stature at Tikal, Guatemala: Implications for Classic Maya demography and social organization. American Antiquity 32: 316-25.

  3. Wright, L. E. and M. A. Vásquez (2003). Estimating long bone length from fragmentary remains: forensic standards from Guatemala. American Journal of Physical Anthropology 120(3): 233-251.

  4. Vásquez Gómez, M. A. (2004). Elaboración de Formularios de Medición de Huesos Largos en Contexto Forense para Estimar Estatura y su Aplicación en Restos Óseos Prehispanicos: El Caso de Tikal. Licenciatura thesis, Universidad de San Carlos de Guatemala.