The dinosaur lineage includes birds.
Archosaurs are a group of diapsid amniotes whose living representatives consist of birds and crocodilians . Dinosaur . The fossil record , however , indicates that birds , which are now termed `` avian dinosaurs , '' are the modern descendants of feathered dinosaurs , having evolved from theropod ancestors during the Jurassic Period . As such , birds were the only dinosaur lineage to survive the mass extinction event . Dinosaurs are represented on every continent by both extant species ( birds ) and fossil remains .