Evolution of birds
Most animals (including humans) evolved from other older animals like apes and dinosaurs. So did birds. The first flying animals were small carnivorous dinosaurs of the Late Jurassic. They then slowly evolved into the birds we have today.
Early Flying Dinosaurs
Some examples of early flying dinosaurs are Archaeopteryx and Sinosauropteryx. They had hair-like feathers which were there to keep them warm. They had a large beak to eat into meat and long, strong claws to easily grab onto their prey. They also had heavy bones which were easily broken.
All early flying birds were carnivores. They fed on smaller dinosaurs and fish. They often caught their own prey and stored any extras to eat them later.
Factors of Evolution
A commonly asked question is ‘What caused evolution?’. The main factor of evolution was change in weather. During the Late Jurassic, the climate got colder. This caused a change in diet. Early flying dinosaurs also grew thick coats of feather to keep them warmer. Their bones also got lighter but stronger to improve flight as they had to fly miles for food.
Change in Diet
Most bird species are either omnivores or herbivores. What drove the change? The weather took a big change during the Late Jurassic. This caused the rivers to freeze and many dinosaurs started to hibernate (this was the beginning of hibernation) or migrate. This left early flying dinosaurs to starve. Their only source of food were plants. Soon, early flying dinosaurs became omnivores and some even became herbivores as generations passed.
References
- Zimmer, Carl. "The origin of Birds". Berkeley University. Retrieved (2015-05-19)
- Davis Hew, Gareth. "Birds arrived comparatively late". PBS. Retrieved (2015-05-21)
- Surtees, Marc. "Did birds evolve from dinosaurs?". Truth in Science. Retrieved (2015-05-20)
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