Related by context. Frequent words. (Click for all words.) 74 Cretaceous 70 Mesozoic 68 Eocene 68 Pleistocene 67 Pliocene 67 Triassic 67 Precambrian 66 Paleozoic 66 Proterozoic 64 Ordovician 63 Jurassic 62 Miocene 62 fossils 61 Devonian 59 theropods 58 glaciation 58 sauropods 58 megafauna 57 Australopithecus 57 dinosaurs 56 prehistoric 56 sediments 56 fossil 56 hominids 56 sedimentary rock 55 mammoths 55 sauropod 55 Homo erectus 55 sedimentary rocks 55 prehistory 55 Archaeopteryx 54 vertebrate 54 hominid 54 taxa 54 fossilized bones 54 fossilized remains 53 tyrannosaurs 53 sedimentary 53 Paleolithic 53 vertebrates 53 volcanism 53 Homo sapiens 52 geologically 52 Neandertals 52 limestones 52 palaeontologists 52 fossilized 52 Ice Age 52 tetrapods 52 volcanic rocks 51 baleen whales 51 intrusive rocks 51 geologic 51 arthropods 51 banded iron 51 calcite 51 mammals 51 dinosaur fossils 50 T. rex 50 intrusives 50 paleo 50 Geologically 50 arthropod 50 Mammals 50 paleontological 50 sedimentary basins 50 paleontologists 49 mastodons 49 Holocene 49 magmatic 49 Neanderthals 49 woolly mammoths 49 Fossils 49 Little Ice Age 49 primate species 49 hydrothermal 49 vertebrate species 49 peridotite 49 diatoms 49 herbivore 49 Triceratops 49 stratigraphy 49 shallow depths 49 dinosaur 49 Archean 48 volcanic islands 48 lake sediments 48 volcanics 48 hunter gatherers 48 Gondwana 48 multicellular 48 pterosaur 48 woolly mammoth 48 Medieval Warm Period 48 granitic 48 single celled organisms 48 mafic 48 lithologies 48 Neanderthal 48 dinos 48 landforms