In Birds Flight is one of the most intriguing animal adaptations. It has evolved independently many times in the course of vertebrate history. Several classes have developed some degree of aerial locomotion. This form of flight depends on the kinetic energy of their moving bodies. Of all these examples, birds have reached the highest level of perfection in flight.
Flight is almost universal to their class.
This paper will investigate the origin of flight in birds. Archaeopteryx, the oldest known bird, will be examined. This ancient bird dates back 150 million years to the Jurassic period. It is important because it has both reptilian and avian characteristics. There are two theories at present which explain the origin of flight in birds.