Complex sentence: In layer 16, radiocarbon dated to 5630 BC, a new type of point appeared, the Blackwater side-notched point, implying the arrival of a group from eastern Nebraska or western Iowa, replacing the previous group which may have moved to the north.
Split into simpler sentences: In layer 16, radiocarbon dated to 5630 BC, a new type of point appeared. These Blackwater side-notched points implied the arrival of a group from eastern Nebraska or western Iowa, replacing the previous group which may have moved to the north.