Related by context. Frequent words. (Click for all words.) 65 Paleolithic 63 Neolithic 63 Neandertals 60 Late Cretaceous 59 Bronze Age 59 #BC [003] 58 Archaic 58 Pleistocene 58 prehistory 57 prehistoric 56 Neanderthals 56 Pliocene 56 Holocene 55 anatomically modern 55 Fertile Crescent 55 Homo sapiens 54 Hellenistic 54 Cretaceous 53 Iron Age 53 ancient Mesopotamia 53 Eocene 53 hunter gatherers 53 Ordovician 52 Neanderthal 52 Han Dynasty 51 Precambrian 51 radiocarbon 51 Middle Ages 51 Australopithecus 51 Oligocene 51 hunter gatherer 51 Mesozoic 51 millennium BC 50 Triassic 50 glaciation 50 thirteenth century 50 Archaeopteryx 50 Sumerians 49 fifteenth century 49 Pre Columbian 49 antiquity 49 Medieval Warm Period 49 #AD [002] 49 radiocarbon dating 49 multicellular 49 Little Ice Age 49 Homo erectus 49 fourteenth century 48 Jurassic 48 megafauna 48 fossils 48 volcanism 48 isotopic 48 ancient civilization 48 Proterozoic 48 ancient 48 Paleozoic 47 mammoths 47 #BC [002] 47 epochs 47 Hittite 47 Prehistoric 47 Achaemenid 47 hominids 47 Ming Dynasty #-# 47 Homo habilis 47 taxa 47 millennia 47 Mesoamerican 47 vertebrate species 46 Mesoamerica 46 hominid 46 Miocene 46 Denisovans 45 Paleo 45 millenniums 45 Sumerian 45 sixteenth century 45 primitive 45 abundances 45 civilization 45 ancient civilizations 45 seventeenth century 45 Oetzi 45 clades 44 primate species 44 #AD [003] 44 semi nomadic 44 theropods 44 pre Columbian 44 paleo 44 Stone Age 44 Roman Empire 44 interbred 44 ca. 44 fossil 44 temperate regions 44 Tang Dynasty 44 temperate zones 44 AD# [001] 44 tetrapods