Final answer:
It is true that birds are the descendants of dinosaurs, specifically theropod dinosaurs. Fossil evidence, such as that of Deinonychus, Archaeopteryx, and Xiaotingia, supports this evolutionary relationship, with shared characteristics between these ancient creatures and modern birds. Modern birds, therefore, represent living descendants of these avian dinosaurs.
Step-by-step explanation:
It is true that scientists think birds are the descendants of dinosaurs. Through extensive research, it has been concluded that birds evolved from a group of bipedal theropod dinosaurs. A pivotal fossil in this discovery was that of Deinonychus, which helped to convince the scientific community of this evolutionary relationship. Furthermore, Archaeopteryx and Xiaotingia are examples of flying dinosaurs, showcasing similarities to modern birds, such as a flow-through respiratory system, which further supports the evolutionary link.
Therefore, the characteristics shared between theropod dinosaurs and birds include the structure of the hip and wrist bones, the presence of a wishbone, and specialized feathers similar to those of modern flight feathers. Despite common belief that all dinosaurs are extinct, modern birds can be considered living representatives of the avian dinosaurs that once roamed the Earth.