Related by context. Frequent words. (Click for all words.) 61 mammals 58 Insects 56 Fossils 56 Mammal 55 Dragonflies 55 Dinosaurs 54 Hummingbirds 54 Songbirds 54 Butterflies 54 Natural History 53 mammal 52 vertebrates 52 Amphibians 51 Reptiles 51 nocturnal animals 51 Humans 51 herbivores 50 Extinct 50 Alligators 50 Giraffes 50 Chimpanzees 50 species 49 vertebrate 49 Human Origins 49 arthropods 49 Parrots 49 mating habits 49 Organisms 49 Mesozoic 49 amphibians 49 mammal species 48 Rattlesnakes 48 Moths 48 Prehistoric 48 Creatures 48 giant tortoises 48 Toads 48 Ferrets 48 Ancestors 48 ungulates 48 reptiles 48 marsupials 47 gibbons 47 Birds 47 flightless birds 47 sauropods 47 invertebrates 47 Skunks 47 Vertebrate Paleontology 47 sauropod 47 Species 47 theropods 47 Archaeopteryx 47 Humpbacks 47 Chimps 47 Rabbits 46 Habitats 46 fossils 46 carnivores 46 baleen whales 46 marmosets 46 primate species 46 songbirds 46 Dinosaur 46 dragonflies 46 Orangutans 45 river otter 45 Populations 45 giraffes 45 journal Current Biology 45 Paleontology 45 Cicadas 45 mating rituals 45 frog species 45 Parasites 45 mammalian 45 Evolutionary Biology 45 Zoology 44 habitats 44 Naturalist 44 dinosaurs 44 Insect 44 megafauna 44 lizards 44 Current Biology 44 mockingbirds 44 nonhuman primates 44 salamanders 44 creatures 44 hominid 44 Caterpillars 44 Whales 44 taxa 44 opossums 44 Triceratops 44 flightless 44 dinos 44 Turtles 44 cetaceans 43 hummingbirds 43 Lesions