Most paleontologists support the view that the birds have been evolved from the group of Theropod Dinosaurs. The descendants of the birds that survived the extinction which occurred 66 million years ago are continuing the dinosaur lineage to the present day.
Dinosaurs are a group of animals that first appeared during the Triassic period and were the dominant terrestrial vertebrates for 135 million years. The relationship among birds and dinosaurs was first pointed out after the discovery of a primitive bird, Archaeopteryx in the nineteenth century.
The birds and dinosaurs share a lot of features. More than 20 percent of fossils of dinosaurs found till date possess feathers. Even small dinosaurs like Microraptor and Anchiornis, had wings. In 2009, Mr. Witmer, a professor of anatomy concluded that these evidences are sufficient enough to demonstrate that avian evolution went through a four winged stage.
The molecular comparison of cellular anatomy protein sequencing of collagen tissue of Tyrannosaurus Rex also demonstrated that the birds are closely related to the dinosaurs. Fossil evidences show that the birds and dinosaurs share many other features like common nest building style, common brooding behaviour, hollow pneumatized bones and gastroliths in the digestive system. So just peek out of your window and see the much evolved living dinosaurs outside. [SOURCE: Bioone]
