Related by context. Frequent words. (Click for all words.) 56 extinct 50 species 48 dodo bird 47 mammal 46 dodo 45 mammals 45 extinct species 44 dinosaurs 43 Extinct 43 mammal species 42 subspecies 42 homo sapiens 42 extinction 42 megafauna 41 dinosaur 41 amphibians 41 creatures 41 amphibian species 40 pikas 40 creature 40 extirpated 40 prehistoric creatures 40 flightless birds 40 critically endangered 40 marsupials 40 Komodo dragons 40 bird species 40 lemurs 39 mammoths 39 rhinoceroses 39 flightless bird 39 giant tortoises 39 herbivorous 39 reptiles 38 tigers 38 frogs 38 domesticated 38 mastodons 38 flightless 38 humans 38 salamanders 38 endangered species 38 Critically Endangered 38 vertebrate 38 frog species 37 triceratops 37 sloths 37 lifeforms 37 Species 37 gorillas 37 woolly mammoth 37 Endangered species 37 Orangutans 36 critically endangered species 36 cave dwelling 36 apes 36 primate species 36 leatherback turtles 36 Homo sapiens 36 herbivores 36 tyrannosaurs 36 toads 36 Mammals 36 lineages 36 moa 36 chimpanzees 36 vertebrates 36 genera 35 carnivore 35 Grizzly bears 35 woolly mammoths 35 habitats 35 Populations 35 Endangered 35 lizards 35 carnivores 35 reptile 35 single celled organisms 35 black footed ferret 35 cetaceans 35 lemur 35 humanoids 35 lizard 35 Sumatran tigers 35 nesting pairs 35 California condors 35 endangered 35 lampreys 35 ape 35 breeding colony 35 saber toothed tiger 34 Mammoths 34 orang utans 34 pterodactyl 34 penguin 34 polar bears 34 genetically distinct 34 herbivore 34 penguins 34 baiji 34 prehistory