Related by context. Frequent words. (Click for all words.) 64 interglacial 64 Cretaceous Period 63 interglacial period 58 Late Cretaceous 57 Pliocene 56 dinosaurs roamed 56 Pleistocene era 54 Homo habilis 54 degrees Fahrenheit warmer 53 Cambrian explosion 53 Australopithecus 53 Australopithecus afarensis 52 Pleistocene 52 Posted -# sec 52 supercontinent 50 Younger Dryas 50 Burgess Shale 49 Ardipithecus 49 H. erectus 49 Ice Age 49 Little Ice Age 49 Homo Sapiens 49 millennia 49 By NBC# NBC# 49 glaciation 49 #BC [003] 48 Beringia 48 trilobites 48 Ordovician 47 hominid 47 prehistoric 47 hominids 47 millenniums 47 Holocene 47 By trevor 47 anatomically modern 47 Carboniferous 47 Cretaceous 47 Eocene 47 Projected completion 47 Paleocene 47 hominins 46 ancient Mayans 46 Homo sapiens 46 Medieval Warm Period 46 Homo erectus 46 preindustrial 46 vertebrate species 46 mass extinctions 46 Neandertals 46 hadrosaur 46 solar nebula 46 genus Homo 46 marine reptiles 46 Its ROA 45 multicellular organisms 45 magnolialover 45 solstices 45 multicellular 45 By GEOFF HOBSON 45 Fertile Crescent 45 sunspot cycle 45 ancient Mesopotamia 45 Paleolithic 45 #BC [002] 45 Triassic 45 megafauna 45 eons 45 shaggles 44 Mayan civilization 44 foraminifera 44 ocean ridges 44 epochs 44 #AD [002] 44 tetrapods 44 marine sediments 44 Sumerians 44 bintx 44 prokaryotes 44 lake sediments 44 nerzog 44 Mesozoic 44 Precambrian 44 equinoxes 44 hominin 44 Archaeopteryx 44 peopling 44 millenia 44 coprolites 44 Oetzi 44 common ancestor 43 FRM averaged #.# 43 sunspot numbers 43 stromatolites 43 prehistory 43 Babylonians 43 Tiktaalik 43 wooly mammoth 43 Help Reason 43 hunter gatherers 43 Oligocene