If you take a look at the bird evolutionary history, it is rather long and highly complex. According to some researchers, birds have evolved from either crocodiles or from a sub-group of archosaurs to which the dinosaurs belonged. However, there is consensus on the fact that evolution of birds took place some time during the early part of the Mesozoic era.
As the dinosaurs evolved gradually into birds, they started making certain evolutionary changes like getting a beak, having a higher rate of metabolism and getting bones that were hollow. Also, the dinosaurs being reptilians were cold blooded animals, while birds are warm blooded. This change took place around the time when mammals evolved from synapsids, who were cold blooded.
The fossil that connects the dinosaur and the modern bird is known as Archaeopteryx. This was a dinosaur bird that flourished in the middle part of the Mesozoic era. The fossil displays many features that are similar to birds and also features that theropod dinosaurs had.
When flying reptiles and dinosaurs became extinct, the evolutionary history of birds got a new impetus. These reptiles were not just competitors but also predators of the birds. Birds flourished as they had the entire sky to themselves.
More Articles :