Related by context. Frequent words. (Click for all words.) 60 Cretaceous Period 54 Late Cretaceous 54 interglacial 54 glaciation 53 taxa 52 Carboniferous 51 Homo sapiens 50 Mesozoic 50 trilobites 50 phylogeny 50 clades 50 Little Ice Age 49 Holocene 49 lineages 49 Pliocene 49 Medieval Warm Period 49 Australopithecus 49 Ordovician 49 Cretaceous 48 Neandertals 48 Gondwana 48 clade 48 Fertile Crescent 48 Pleistocene 48 Oligocene 48 lake sediments 47 genus Homo 47 megafauna 47 continental drift 47 landmasses 47 Eocene 47 lithosphere 47 Quaternary 47 terrestrial ecosystems 47 volcanic islands 47 genera 46 common ancestor 46 Australopithecus afarensis 46 hominins 46 moa 46 Rig Veda 45 Precambrian 45 mass extinctions 45 dinosaurs roamed 45 femtoseconds 45 Triassic 45 gigatonnes 45 baleen whales 45 mass extinction 45 Homo erectus 45 isotopic 45 hominid 44 #BC [003] 44 Ardipithecus 44 hominin 44 basalts 44 Homo habilis 44 Paleozoic 44 volcanism 44 millennia 44 temperate zones 44 hominids 44 crustal 44 vertebrate species 44 epochs 43 homo sapiens 43 mudstone 43 paleo 43 plate tectonics 43 GeV 43 mtDNA 43 ENSO 43 Tiktaalik 43 phylogenetic 43 multicellular 43 tetrapods 43 prehistory 43 anatomically modern 43 archaea 42 primate species 42 speciation 42 Han Dynasty 42 Archaea 42 millenniums 42 interbred 42 subtropical regions 42 stalagmite 42 species 42 Archaeopteryx 42 Neanderthals 42 temperate regions 42 tyrannosaurs 42 atmospheric CO2 42 glacial melt 42 Weddell Sea 42 Miocene 42 sunspot 42 Jurassic 41 equator 41 tyrannosaur 41 genus