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Are modern birds considered living dinosaurs?

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Illustration showing various dinosaur species drawn to scale and grouped by geologic era: Late Cretaceous, Early Cretaceous, Jurassic, and Triassic. Dinosaurs range from large species like Brachiosaurus and Tyrannosaurus to smaller ones like Velociraptor and Compsognathus, with a human silhouette included for size comparison. Measurement bars at the bottom indicate 1 meter and 3 feet for scale reference. — dinosaur A selection of dinosaurs grouped by the geologic interval in which they lived.

Yes, modern birds are considered living dinosaurs. Scientific consensus, supported by extensive fossil evidence, establishes that birds evolved from a lineage of small theropod dinosaurs more than 150 million years ago.12

Under the principles of biological classification, organisms are categorized within the groups from which they evolved. Because birds are nested within the theropod group, they are classified as both birds and dinosaurs, much in the same way that humans are classified as both primates and mammals.2

This evolutionary relationship is confirmed by numerous shared anatomical features, such as specific structures in the wrist, pelvis, and foot, as well as the presence of feathers in many non-avian dinosaur fossils. These discoveries demonstrate that birds did not emerge as a separate group that bypassed the dinosaurian lineage; rather, they represent the surviving branch of the theropod family tree.312