younger bound -1400 Ma Calymiano calymmij Calymmian Period Kalym kalymnium Statherian Period Precambrian Supereon a2.1.2.3 Mesoproterozoic Era Calymmiense Kalymis Calymmium Base of Ectasian Ectasian Period Geologic Time Scale (2018) Calymm Calymm Calymmiën Калим calymmi Calymmian Calym calymmiano Base of Mesoproterozoic kalymmium Paleoproterozoic Era older bound -1600 Ma 盖层纪 Proterozoic Eon Kalymmium カリミアン紀 Calymmien Calymmien