The remains are thought to be from the Middle Archaic period and were found near a site where scientists believe early Iowans harvested, cooked and consumed clams thousands of years ago.
Ancient ash and charcoal remains, apparent signs of a Stone Age clambake, also were uncovered.
Studies are ongoing, but it is one of the earliest and best examples of an Archaic site discovered in Iowa. Its exact location is not being revealed because of fears of looters.
Story: Jason Clayworth, Des Moines Register| Photo: U of I, State Archaeologist’s Office