Related by context. Frequent words. (Click for all words.) 79 Cretaceous Period 67 Late Cretaceous 64 Cretaceous 63 interglacial period 60 dinosaurs roamed 60 Pleistocene 60 dinosaurs 59 Carboniferous 59 Mesozoic 59 trilobites 59 Triassic 59 megafauna 58 interglacial 58 Fertile Crescent 57 anatomically modern 57 marine reptiles 57 Pliocene 56 Little Ice Age 56 Ice Age 55 prehistoric 55 mammoths 55 Precambrian 55 Homo sapiens 55 tyrannosaurs 55 carnivorous dinosaurs 55 Younger Dryas 55 hominins 54 Ordovician 54 Eocene 54 prehistory 54 woolly mammoths 54 Mammoths 53 glaciation 53 Neandertals 53 Australopithecus 53 fossils 52 fossilized remains 52 Homo habilis 52 Oligocene 52 Jurassic 52 theropods 51 tetrapods 51 Australopithecus afarensis 51 Paleolithic 51 Quaternary 51 tyrannosaur 51 Homo erectus 51 Paleozoic 51 Neanderthals 51 theropod 51 hominids 50 mass extinction 50 Holocene 50 Medieval Warm Period 50 multicellular 50 Archaeopteryx 50 Tiktaalik 50 fossil 50 plesiosaur 50 sauropods 50 genus Homo 50 mass extinctions 50 #BC [003] 50 Gondwana 50 African savanna 49 Miocene 49 Han Dynasty 49 mammals 49 millenniums 49 Weddell Sea 49 overhunting 49 Mesoamerica 48 Ardipithecus 48 sauropod 48 Bronze Age 48 prehistoric creatures 48 hominid 48 hadrosaur 48 vertebrate species 48 T. rex 48 Neolithic 48 hunter gatherers 48 Kalahari Desert 48 temperate zones 48 microfossils 48 Denisovans 48 dinosaur fossil 48 preindustrial 48 hominin 48 dinosaur fossils 48 fossilized bones 47 Lower Cretaceous 47 Ming Dynasty #-# 47 marine sediments 47 pterosaur 47 Neandertal 47 HMS Beagle 47 Ross Ice Shelf 47 Polar Regions 47 Fossils 47 single celled organisms