The pottery changed at Canas while the stone tools stayed the same

At the Canas site in Puerto Rico the Saladoid and Ostiones layers sit one above the other with a clean line between them, and the early conclusion drawn from that line was that two separate cultures had occupied the site in turn. The difficulty with that reading is that nobody could find anywhere for the second culture to have come from. No source region, no migration route. So the material was examined again, and the current view is that Ostionoid pottery grew out of the Saladoid tradition in the islands themselves, with recent argument pointing to the eastern Dominican Republic and the exchanges taking place there. Other evidence supports continuity. Stone toolmaking runs straight through the transition with no equivalent break. What changed was the pottery, and pottery is the loudest thing in an excavation. The change marks the beginning of a period in which the Greater Antilles broke into regions, each developing a look of its own.

At Cerrillo, in the west of Puerto Rico, there is a place where people went to work flint. It reads as a workshop rather than a village, since the ground holds the waste of tool manufacture, the flakes and rejected pieces that come off shaping a nodule into something usable. Cerrillo was busiest during the changeover into the Ceramic age, when pottery was being adopted and settlement was reorganising, and the flint had been quarried there before that. The evidence indicates people were taking nodules out of the same deposit back in the Archaic age. That continuity is the interesting part. A source of good stone gets found once and then used for as long as anyone needs stone, across changes in pottery, diet and social arrangement that archaeologists treat as boundaries between cultures. The people at the flint outcrop in the seventh century were going to a place their predecessors had gone to for centuries, for the same reason.