Eric Walker added 2019-10 - New research supports hypothesis that asteroid contributed to mass extinction - Wits University to Younger Dryas impact hypothesis (YDIH), Robberg stone artefact industry and Clovis culture

Eric Walker added a number of topics and a number of links to Neolithic, and added Neolithic to Archeology, Stone Age and History, prehistory and geologic time

Eric Walker added 2019-10 - New research supports hypothesis that asteroid contributed to mass extinction - Wits University to Robberg stone artefact industry, and added Robberg stone artefact industry to Neolithic