Birds (about 208 MYA)
Birds are feathered, winged, two-legged, warm-blooded, egg-laying vertebrates. They live worldwide and range in size from the 5 cm (2 in) Bee Hummingbird to the 2.75 m (9 ft) Ostrich. The fossil record indicates that birds emerged within the theropod dinosaurs during the Jurassic period. Around 150 million years ago. Modern bird are characterized by feathers, a beak with no teeth, the laying of hard-shelled eggs,
a high metabolic rate, a four-chambered heart, and a lightweight but strong skeleton.
a high metabolic rate, a four-chambered heart, and a lightweight but strong skeleton.
Snakes (about 144 MYA)
Snakes are reptiles. Snakes grow out of their skin and grow new skin.Snakes are elongated, legless, carnivorous reptiles. Many species of snakes have skulls with many more joints than their lizard ancestors, enabling them to swallow prey much larger than their heads with their highly mobile jaws.Living snakes are found on every continent except Antarctica, in the Pacific and Indian Oceans, and on most smaller land masses.