How Did Birds Evolve? This is a challenging topic in science. Birds have soft, fragile skeletons and fly in the air, making fossilization rare. As a result, fossil evidence regarding the origins of birds is very scarce; worldwide, only five fossil cases of primitive birds have been discovered.
All five of these cases were found in the Bavaria region of Germany and date back approximately 150 million years. They have proven to be ancestors of modern birds. The fossil features very distinct feather impressions, clearly differentiating between primary and secondary feathers, and even tail feathers. The forelimbs evolved into wings, while the hind limbs had feet with four toes (three in front and one behind). The clavicles fused to form a wishbone, and the pelvis extended backward. These characteristics are all indicative of modern birds.
A fossil of the prehistoric bird (Photo: bellarmine)
However, intriguingly, it had teeth in its mouth, and its wings had three claws. The bones of the hands and feet were separate. It also had a long tail composed of distinct bony segments. These features are characteristic of reptiles. Research indicates that this bird represents a transitional form from reptiles to birds, which is why it is referred to as a “transitional bird.”
Through examinations, it has been determined that the minimum flight speed of this transitional bird was 7.6 meters per second. It was capable of flapping its wings to fly but could not do so for long durations.
How did the transitional bird shift from a ground-dwelling lifestyle to one of flight?
There are two main perspectives:
– One theory suggests that primitive birds climbed trees and gradually transitioned to short flights, eventually mastering gliding.
– The other theory posits that primitive birds ran on two legs while using their forelimbs to catch prey, leading to the eventual evolution of wings.
Although primitive birds have only been found in fossils, they provide crucial evidence for the origins of birds and are considered the ancestors of modern birds.
The skeleton of the transitional bird (Photo: fsteeman)
