Archaeopteryx is a dinosaur belonging to the family Archaeopteryx in the order Saurischia. The size is similar to that of medium-sized birds today. Flexible head, slender neck, short body, long and stiff tail; The arms, forelimbs, and long tail are covered with feathers, while the thumb faces backwards; It has sharp teeth, claws on its wings, sharp and curved claws at the end of its hind toe, and a bony coccyx. Living in the late Jurassic period, mostly distributed in southern Germany. Carnivorous animals feed on insects and fish. Not strong in flying ability, only suitable for short distance flight; Unable to live in trees for a long time, but skilled at running on the ground. Scientists believe that it may be the first terrestrial organism to transform into a bird.