Related by context. Frequent words. (Click for all words.) 32 Arctic permafrost 31 Late Cretaceous 31 Precambrian 31 carbonite 29 Mesozoic 28 Pleistocene era 27 Carboniferous 27 Otzi 27 Cretaceous 26 supercontinent 26 genus Homo 26 giant tortoise 26 Eocene 26 planet Krypton 25 wooly mammoth 25 Homo floresiensis 25 Pliocene 25 megafauna 25 glaciation 25 Cretaceous Period 24 H. erectus 24 Homo erectus 23 Homo Sapiens 23 interglacial 23 mummified 23 Oetzi 22 tyrannosaurus rex 22 locked 22 Ellesmere Island 22 triceratops 21 hominid 21 woolly mammoths 21 dinosaurs roamed 21 fossilized remains 21 Ice Age 20 woolly mammoth 20 Australopithecus 20 Pleistocene 20 brontosaurus 19 mammoths 19 permafrost 19 cave dwelling 19 temperate forests 19 Mummified 18 Tyrannosaurus Rex 18 hominins 18 Poinar 18 radiocarbon 18 hominids 18 dinos 17 Arctic tundra 17 Homo sapiens 17 dinosaur 17 Younger Dryas 17 Tyrannosaurus rex 17 Neandertals 17 T rex 17 cave 17 African savannah 17 prehistoric 17 subarctic 17 fossils 16 trilobites 16 domesticated 16 solar nebula 16 radioactive decay 16 Neanderthal 16 fossilized 16 African savanna 16 interglacial period 16 fossil 16 coprolites 15 icecaps 15 Paleontologists 14 dinosaurs 14 T. rex 14 eons 14 single celled organisms 13 Zimov 13 marine reptiles 13 tar pits 13 kelvin 13 polar ice 12 Antarctic ice 12 musk oxen 12 Microorganisms 12 mastodons 11 gigatons 11 prehistoric creatures 11 Niels Bohr Institute 10 preindustrial 10 mass extinction 10 atmospheric methane 9 oxygen isotopes 9 Giant pandas 9 age 9 homo sapiens 5 gigatonnes 5 Industrialized nations 4 extinctions 0 co2