The relationship between Andean coca use and dental deposits is explored through the use of scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Elemental analyses of samples of large dental deposits from archeologically recovered skeletons from Ecuador dating between 500 B.C. and A.D. 1532 are compared with those of normal calculus deposits of individuals from North America (modern and precontact), of normal tooth structure and of samples of alkali recovered from Ecuadorian artifacts thought to have been employed in coca use. Spectral analysis revealed homogeneity among all dental samples (deposits and structure) and that they are distinct from the elemental pattern revealed in the analysis of the artifact alkalis.

A method is described for using vinyl polysiloxane dental impression material to make high definition casts from ceramic objects that bear negative imprints of textiles. Casts made from impressions found on prehistoric ceramic figurines from Ecuador were examined under magnification and features of the yarns and weaves were described. The data are used to reconstruct prehistoric spinning and weaving technology. The use of cloth in figurine manufacture and the reconstructed textile technology are interpreted in spatial, temporal and cultural perspectives.

This article begins with a description of excavations in the Las Vegas type site on the Santa Elena Peninsula, Ecuador. A pre-Las Vegas phase (11,000 to 10,000 B.P.) is defined provisionally, and the Early Las Vegas (10,000 to 8000 B.P.) and Late Las Vegas (8000 to 6600 B.P.) phases are described from artifacts, burials, settlement data, faunal remains, pollen, and phytoliths. The Las Vegas people were unspecialized hunters, fishermen, and gatherers living in a littoral zone who added plant cultivation to their subsistence system before 8,000 years ago. Evidence for bottle gourd (Lagenaria siceraria) and primitive maize (Zea mays L.) was found in the Las Vegas type site. The differences between the modern, semiarid environment and the environment of the preceramic period are accounted for without hypothesizing climatic change. Las Vegas is interpreted as a local manifestation of an early tropical forest cultural tradition out of which developed the ceramic-stage cultures of the Ecuadorian coast.

Of the four late Pleistocene and early post-Pleistocene lithic complexes defined by Edward P. Lanning, only one, the Las Vegas complex, is supported by existing evidence from the Santa Elena Peninsula of southwest Ecuador. The Achallan culture, previously defined by Stothert and assigned to the post-Las Vegas period, is now unsupported by satisfactory evidence.