Related by context. Frequent words. (Click for all words.) 72 Cretaceous 68 Eocene 67 Miocene 67 Mesozoic 67 Triassic 64 Devonian 63 Pliocene 60 Ordovician 60 Pleistocene 56 Proterozoic 55 Precambrian 55 dinosaur 53 dinosaurs 52 fossil 52 fossils 50 Fossils 50 sandstones 50 prehistoric 49 Holocene 49 Paleolithic 47 geologically 47 Triceratops 46 dinosaur fossils 46 sedimentary rocks 46 Prehistoric 46 fossilized 46 Tertiary 46 dino 46 fossilized remains 45 sauropods 45 Archean 45 paleo 45 Dinosaur 45 geologic 44 dinos 44 Australopithecus 44 Ice Age 44 T. rex 44 Stone Age 44 hominid 43 sedimentary 43 T. Rex 43 sedimentary rock 43 sauropod 43 undrilled 42 epithermal 42 shales 42 pterosaur 42 Archaeopteryx 42 hydrocarbon bearing 42 mammoths 42 stratigraphy 42 mineralized 42 Great Rift Valley 42 Tyrannosaurus Rex 42 woolly mammoth 42 sandstone 41 Sandstone 41 sediments 41 caldera 41 geological formations 41 hydrothermal 41 Bronze Age 41 mastodon 41 Cambrian 41 Neanderthals 41 T rex 40 Iron Age 40 Neanderthal 40 paleontologists 40 Formation 40 Mammals 40 mastodons 40 Permian 40 Paleo 40 palaeontologists 40 anticline 40 glaciation 40 volcanic 40 volcanism 40 uranium mineralization 40 stratigraphic 40 geological 40 paleontologist 40 Neolithic 40 hominids 40 volcanic rocks 39 Tyrannosaurus rex 39 Gondwana 39 paleontological 39 massive sulphide mineralization 39 Homo erectus 39 rock 39 sands 39 Archaic 39 diorite 39 lode 39 geologic formations 38 hydrothermal alteration 38 shallow depths 38 Mineralized