Related by context. Frequent words. (Click for all words.) 65 Late Cretaceous 63 taxa 62 terrestrial ecosystems 62 marine reptiles 62 temperate forests 61 megafauna 60 Cretaceous Period 60 Pleistocene 60 mammals 60 Paleocene 60 Mesozoic 59 morphologically 59 landforms 59 morphologies 58 species 58 planktonic 58 marine invertebrates 58 trilobites 58 landmasses 58 marine sediments 58 biome 57 clades 57 tetrapod 57 theropod 57 vertebrate 57 feathered dinosaurs 57 H. erectus 56 Beringia 56 Cambrian explosion 56 multicellular organisms 56 ecologies 56 carnivorous dinosaurs 56 Carboniferous 56 calcareous 56 avian species 56 lineages 56 lavas 56 foraminifera 55 vertebrate species 55 biota 55 Pliocene 55 prokaryotes 55 crocodilians 55 Eocene 55 fossils 55 biogeography 55 mammalian species 55 microfossils 55 hominins 54 diatoms 54 biodiversity hotspots 54 Burgess Shale 54 Younger Dryas 54 diatom 54 basalts 54 theropods 54 vertebrates 54 volcanism 54 Ordovician 54 morphological 54 Tiktaalik 54 biomes 54 mammal 54 supercontinent 54 phylogeny 54 interglacial period 54 hydrothermal vent 54 Neandertals 53 morphology 53 Paleozoic 53 ecological niches 53 lava tubes 53 stromatolites 53 arthropod 53 herbivorous 53 lithosphere 53 latitudinal 53 clade 53 overhunting 53 subfamily 53 Quaternary 53 prehistory 53 Mammals 52 Precambrian 52 mammal species 52 genera 52 mammoths 52 multicellular 52 skink 52 Triassic 52 continental crust 52 volcanic islands 52 Mammoths 52 baleen whales 52 fauna 52 speciation 52 calcite 52 tapirs 52 Cretaceous 52 hominin 52 tyrannosaur