• Korean Journal of Poultry Science
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• v.49 no.3
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• pp.167-180
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• 2022

Aves including chickens are currently one of the most representative vertebrates on the planet. More than 10,000 bird species are distributed among various regions around the world. Dinosaurs, which evolved from archosaurs, were once assumed to have gone extinct during the Cretaceous-Paleozoic extinction period. Since the mid-1990s, abundant dinosaur fossils have been found in China and various other parts of the world. Research articles on phylogenetic, evolutionary, and genomic studies of fossil taxa show that birds are living theropod dinosaurs. This review describes the link between birds and dinosaurs based on studies of their skeletal structures, feathers, respiratory organs, chromosomes, and metabolism. Birds are the only theropod dinosaurs that survived the mass extinction 66 million years ago. Dinosaurs did not go extinct and we are still living in the age of the dinosaurs.