Cynodont, the ancestor of mammals. More like mammals than reptiles. Some live in pairs in caves. Ancient creatures, only two large canine molars have been found in the petrified forest of Arizona. Most canines are carnivorous animals, with very few exceeding 90 centimeters in length. They have many similarities with mammals. Both canines and mammals can breathe while chewing food. They all have several different types of teeth. Like mammals, canines have whiskers and perhaps body hair. Dogtooth beasts have their limbs located beneath their bodies and can run quickly.

The Pterosaur is a member of the Hadrosauridae family in the order Ornithischia, also known as the Pterosaur. The most obvious feature is the crown extending from the head, which is rod-shaped and longer than other crowned dinosaurs. There is a thin tube in the crown of the head that makes a sound when air passes by, and the secondary comb dragon uses it for "conversation". The forelimbs of the Pterodactylus can support its body, swim, and wade through water. Living in the late Cretaceous period, this organism was discovered in North America and lived along inland waterways. Eating plants, the habitat is home to many evergreen trees, ferns, and a small number of flowering plants. Collective living, with a keen sense of hearing and smell, will use a headband to sound an alarm signal when danger is detected.

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.

Iguanosaurus is a dinosaur genus that lived in the early Cretaceous period. The name means "iguana teeth" and is the first recognized dinosaur, the second officially named dinosaur type, and one of the original three dinosaur species used to define dinosaur classification.