This question takes us into the fascinating world of evolutionary biology. Dinosaurs are indeed classified as reptiles, but they are part of a specific group called archosaurs, which also includes modern birds and crocodilians. The connection between birds and dinosaurs lies in the fact that birds are considered the descendants of theropod dinosaurs, a group that includes well-known species like Tyrannosaurus rex and Velociraptor.
While it might seem that modern reptiles like lizards and snakes should be the closest relatives of dinosaurs due to their shared classification, it’s important to understand that evolution is not a straightforward line. Instead, it is more like a branching tree, where some branches lead to extinction, like the non-avian dinosaurs, while others continue to thrive and evolve, as in the case of birds.
Birds share many characteristics with theropod dinosaurs, such as feathers, hollow bones, and specific features of their hips and limbs. The evolutionary adaptations that occurred over millions of years led to the emergence of birds from their dinosaur ancestors, making them the closest living relatives of these ancient reptiles today. In summary, while both modern reptiles and birds share a common ancestry with dinosaurs, birds are the direct descendants of a particular lineage of dinosaurs, highlighting the intricate and sometimes surprising paths of evolution.