The main points to the transition from reptile to bird are the evolution from scales to feathers, the evolution of the beak (although independently evolved in other organisms), the hallofication of bones, development of flight, and warm-bloodedness.
The evolution of birds is thought to have begun in the Jurassic Period, with the earliest birds derived from theropod dinosaurs.
Birds are the only animals that have feathers, which are made of keratin, just like your hair and fingernails. A bird’s wings have the same bones as a human arm, but they are arranged differently. Some of the bones in a bird’s skeleton are hollow. This makes the bird light enough to fly. There are more than 9,800 known types of birds.
All birds:
The evolution of birds is thought to have begun in the Jurassic Period, with the earliest birds derived from theropod dinosaurs.
Birds are the only animals that have feathers, which are made of keratin, just like your hair and fingernails. A bird’s wings have the same bones as a human arm, but they are arranged differently. Some of the bones in a bird’s skeleton are hollow. This makes the bird light enough to fly. There are more than 9,800 known types of birds.
All birds:- Are vertebrates (which means they have a backbone or spine).
- Are endothermic. Also known as “warm-blooded,” endothermic animals regulate their own body temperature which allows them to live in almost every climate on earth.
- Have feathers.
- Lay eggs with hard, waterproof shells. The parent birds incubate the eggs until they hatch, and care for their young.
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