Related by context. Frequent words. (Click for all words.) 61 Pliocene 60 Late Cretaceous 58 Carboniferous 57 Eocene 57 Pleistocene 56 Paleolithic 56 interglacial 55 Cretaceous Period 55 Mesozoic 54 hominins 54 Cretaceous 54 prehistoric 54 interglacial period 54 Neolithic 53 microfossils 52 Quaternary 52 Neandertals 52 hominids 51 Homo erectus 51 Paleocene 51 hominid 51 hominin 51 Homo sapiens 51 Ordovician 51 fossils 50 Neandertal 50 Oligocene 50 megafauna 50 Australopithecus 50 genus Homo 50 continental crust 49 radiocarbon dating 49 prehistory 49 radiocarbon 49 Triassic 49 taxa 49 Precambrian 49 abundances 49 glaciation 49 marine sediments 48 Archaeopteryx 48 isotopic 48 fossil 48 Younger Dryas 48 Homo habilis 47 theropods 47 lavas 47 tyrannosaur 47 Homo Sapiens 47 Miocene 47 zircons 47 volcanism 47 Australopithecus afarensis 47 middens 47 basaltic 47 Holocene 47 sauropod 47 coprolites 47 theropod 47 multicellular 47 anatomically modern 46 fossilized 46 Neanderthal 46 Tiktaalik 46 Fossils 46 stalagmite 46 lake sediments 46 Bronze Age 46 fossilized remains 46 hunter gatherers 45 Lower Cretaceous 45 Prehistoric 45 Paleozoic 45 morphological 45 basalts 45 Medieval Warm Period 45 #BC [003] 45 flint tools 45 pterosaur 45 preindustrial 45 Proterozoic 45 multicellular organisms 45 tetrapods 45 subfamily 44 palaeontologists 44 oxygen isotopes 44 Neanderthals 44 landforms 44 vertebrate species 44 trilobites 44 diatom 44 neolithic 44 dinosaurs roamed 44 phylogeny 44 common ancestor 44 marine reptiles 44 dinosaurs 44 marine invertebrates 44 Supplementary Fig 44 hadrosaur 43 tyrannosaurs