CULTURAL DEVELOPMENT IN 
CENTRAL MESOAMERICA 
By ROMAN PmA CHAN 
Instituto Nacional de Antropologia e Historia, Mexico, D.F. 
INTRODUCTION 
Expanded archeological investigations of recent years, as well as 
the discovery of additional sites possessing traits identified with the 
Mesoamerican culture pattern, make it possible to identify three im- 
portant fluctuations in the boundaries of this area. During the Forma- 
tive Horizon, the northern boundary can be drawn from the Rio 
Panuco to Cihuatlan, Colima, the imaginary line crossing the lakes of 
Chapala and Cuitzeo, and following the Rio Moctezuma to Tampico 
(fig. 1). Sites such as Panuco (Veracruz), Chupicuaro (Guana- 
juato), Jiquilpan and El Openo (Michoacan), and Morrett (Co- 
lima) have occupations of Formative age (fig. 3). In the south, this 
horizon is represented as far as the Rio Ulua and Lake Yojoa, and 
El Salvador, in sites such as Yarumela, Yojoa, Travesia, Cerro 
Zapote, and Tovar. 
During the Theocratic Period of the Regional Developmental Ho- 
rizon (fig. 4), the northern boundary expands as far as Soto La 
Marina, San Luis Potosi and northern Jalisco, continuing along the 
Rio Santiago as far as the Rio Sinaloa. By contrast, the southern limit 
retreats to the Rio Motagua and Rio Lempa along the frontier of 
Honduras and El Salvador. 
Finally, during the 16th century the limits of the area readjust 
once more. The northern limit is set by the Rio Panuco and the Rio 
Lerma, while the southern limit passes from the mouth of the Rio 
Motagua to the Gulf of Nicoya, via Nicaragua, representing a con- 
traction of the northern frontier and an expansion of the southern 
one. 
The first fluctuation may be the result of diffusion toward the 
south of basic elements evolved in the central plateau and Gulf coast 
during the Formative Epoch. The second is perhaps the result of 
regional differentiation, which produced autonomous theocratic so- 
cieties strongly linked by commercial ties. The final fluctuation is the 
product of expansion, probably of a military nature, of northern 
groups toward the south. 
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