Clay and temper trace Tampa Bay's Mississippian pottery to potters who moved there

A design can be copied by anyone who has seen it. The clay a potter digs, the temper mixed into it and the way a vessel is built up are habits learned in one place over years, and those are the details the Florida Museum team went after, working below the surface motifs ^[10]. "We were curious to find out if these vessels were imported from the heartland by trade, if they were local imitations of Mississippian motifs, or, as we ultimately found, if they were made by migrants who had made their way into communities in Tampa Bay to take up shop and residency there," said Trevor Duke ^[6], who began the work as a doctoral dissertation at the University of Florida and later expanded it with a larger set of samples ^[7].

The plain sherds are the comparison group. Tampa Bay's common wares were plain and molded, and against that baseline the decorated vessels had distinct high-quality clay, a different temper and a different production method, which the team took as evidence of specialized knowledge and materials the existing residents did not have ^[11]. The phys.org report, which describes the clay as distinct and high quality, leaves out the measurements that placed its source near Tampa Bay rather than in the north.

The trait mismatch is what kept the question open. "Tampa Bay sites had some Mississippian-like traits such as platform mound-village complexes and iconography, but lacked others, like maize agriculture and shell-tempered pottery. The Mississippian-looking pottery has always begged the question: How did this stuff wind up in Tampa Bay?" said Neill Wallis, curator of Florida archaeology, bioarchaeology and the Ceramic Technology Laboratory at the Florida Museum ^[9]. Safety Harbor communities built flat-topped mounds and gathered into small chiefdoms, and they fed themselves on fish and marine resources instead of maize ^[13]. The largest village was home to the Tocobaga, with smaller Mocoso, Pohoy and Uzita chiefdoms nearby, all of them short of the political power of the northern hubs ^[14].

Fifty-eight sherds is the whole denominator, and the decorated group is smaller still, since plain wares are counted in that total ^[4][17]. What that sample can establish is how a particular set of vessels was made. How many people moved south, when they arrived, whether the workshop lasted a season or four generations: those questions stay open.

The sherds themselves have been available since roughly the 1920s ^[1]. Surface designs alone could not fix where the pots were made, and curators shelved them for want of instruments and expertise ^[15]. For years the range maps stopped short of peninsular Florida ^[2].