Cueva de los Ladrones (Coclé), but they did discover preceramic deposits with a unifacial stone industry (5000–2000 b.c.) lying over other deposits with Monagrillo ceramics (2500–1000 b.c.). The year before, Anthony Ranere recorded a similar sequence and materials at the Aguadulce Shelter. These discoveries of inland sites around Parita Bay rekindled interest in coastal Monagrillo and Cerro Mangote, where, in 1975 and 1979, Ranere and Linares executed careful tests by a coring survey of the Parita Bay littoral. They verified and refined Willey’s coastal progradation sequence, improved radiocarbon dating, and, aided by Patricia Hansell’s study of shellfish exploitation, vastly improved the database relevant to subsistence economy.

Linares and Ranere began this project believing that Parita Bay preceramic and early-ceramic peoples were not farmers. But for her 1975 master’s thesis, Dolores Piperno found maize phytoliths at the Aguadulce Shelter associated with Monagrillo potsherds. That maize was also cultivated in preceramic times was apparent from pollen and phytolith analyses of column samples obtained in 1981 at Cueva de los Ladrones. The hypothesis that Pacific Panamanian populations adopted farming and cultivated domesticated maize and root crops long before the development of sedentary, nucleated villages with stone statuary, clay vessels, and metal jewelry was fortified by Piperno’s analysis of archaeological sediments from the Cueva de los Vampiros, the Los Santanas rock shelter, and, more recently, the Aguadulce Shelter, which she retested with Ranere in 1998. Also in 1998, Piperno and Irene Holst discovered starch grains from maize, yuca, sweet potatoes, squashes, and arrowroot embedded in late-preceramic and early-ceramic (5000–1000 b.c.) grinding stones. Lynette Norr, who has undertaken a detailed study of stable carbon and nitrogen isotopes in Panamanian pre-Columbian skeletons, has confirmed the heavy consumption of maize and coastal resources at Parita Bay sites, including Sitio Sierra, La Mula–Sarigua, Cerro Juan Díaz, and Cerro Mangote. Discrepancies between bone-collagen radiocarbon dates and the stratigraphic position of Cerro Mangote’s burials, however, await clarification. Norr is currently reassessing the Zapotal site, discovered by Willey, in order to determine whether it was a fishing camp or a more permanent (agricultural) settlement.

Until the 1980s site surveying in Panama relied on intuition, geography, and visibility. From 1981 to 1986 researchers in the Proyecto Santa María used randomly selected, 0.5-kilometer-wide linear transects and purposive foot surveys to sample a 184,000-square-kilometer watershed in central Panama. Small tests were excavated in stratified rock shelters (Cooke and Ranere 1999). An early-preceramic component (8000–5000 b.c.) was added to the Gran Coclé sequence, and evidence was found for late-glacial occupation, both at the Corona rock shelter and in cores extracted from Lake La Yeguada, where pollen, phytolith, and charcoal distributions alluded to human-induced burning and clearance of late-glacial-stage Quercus-Ilex montane forests after about 9000 b.c. In 1988 Ranere discovered new Paleo-Indian locations at Lake Madden and La Mula–Sarigua, where Clovis-like tools were manufactured from outcropping agate (Ranere and Cooke 1991, 1996). A 1998 lakeshore survey of Lake La Yeguada by Georges Pearson (1999) supported the sediment record for early human activity by locating several quarry sites with bifacially worked chalcedony tools, including one fluted point.

The collation of paleoecological and archaeological data vouched for the continuous occupation of the Santa María drainage after about 9000 b.c., the initiation of plant cultivation during the early Holocene (8000–2500 b.c., when the climate became wetter and warmer), and the nucleation of farming populations in colluvial bottomlands at the end of the first millennium b.c. In 1988 Hansell recorded a 50- to 80-hectare village at La Mula–Sarigua, where specialized grinding and cutting stone tools were associated with a new polychrome pottery style (La Mula). This pottery has recently been well dated at the Cerro Juan Díaz site to between 250 b.c. and a.d. 200.