The largest pterosaur is Fengshen Pterosaur (Fengshen Pterosaur). The length of the deployed wing is10 ~12m, which is equivalent to the size of an airplane.
Hermit forest pterosaur
The smallest arboreal pterodactyl fossil, the pterodactyl Youlin, has a wingspan of only 25 cm, which is about the size of a swallow.
Allodontic dragon
Allosaurus (another reptile that is not a dinosaur, also called Allosaurus) was first discovered in Cape Province and lived in the early Jurassic. At most, it is only 1.5 meters long. So it is called Allosaurus mainly because it is different from other dinosaurs. It has three different types of teeth, that is, small teeth like mammalian incisors that grow in front of the jaw, long teeth like canine teeth that grow behind the incisors, and teeth with broad ridges on the buccal teeth. This tooth combination only exists in mammals and reptiles, and scientists still can't figure out how Allosaurus used its jaw when chewing. People think it eats plants, so it has big tusks, which can help it bite off thick plants, and can also be used as defensive weapons or gender characteristics. Only male teeth are as long as fangs, or gender characteristics, and only male teeth are as long as canine teeth. It has short forelimbs and long hind limbs, a long tail and a short neck to keep balance. Its hind legs are very similar to birds, and the tibia and fibula heal up to the tarsus, making the hind legs strong and stable. Allosaurus is a good running animal and runs very fast. Its forelimbs are also very strong and flexible, suitable for digging plants on the ground and can accurately grab plants. Its name comes from its high ridge. This dinosaur was first discovered in England and lived in the early Cretaceous. It is only more than 2 meters long and only 60 centimeters high. Its forelimbs are very short, with five short fingers on them. Its hind limbs are much larger than its forelimbs, with four toes and short claws on both fingers and toes. It has a hard tail and runs very fast. Once thought to be a dinosaur that could climb trees. Because at that time, I mistakenly thought that the first toe of its hind leg could extend backward and the other three toes could extend forward, that is, it could grasp branches like a bird. But after careful study, it was found that the first toe of its hind limb also pointed forward and could not catch the branches, so it also lived on land. It picks delicious buds and buds from branches with a long and narrow beak with horny skin. This sharp beak has an unusual bite force. Dinosaurs are very picky when they eat. Its beak and mouth can grow new ones after being worn out. When living mammals eat plants, they always move their jaws and chew left and right. Pterosaurs are different. Its skull has a joint, like a diagonal hinge. When the mouth is closed, it can make the upper and lower jaws alternately move outward and chew food with buccal teeth. There are several kinds of pterodactyl, which have formed a taxonomic "family". Members of Cladosporiaceae were found from the Middle Jurassic to the Late Cretaceous, some of which were 4 meters long. Late Jurassic to Early Cretaceous was the heyday of odontosaurus, which was found in North America, Europe, Africa, Asia (including China), Oceania and Antarctica.
iguanodon
Iguanodon and hadrosaurs are members of the suborder Avipoda, but the number of hadrosaurs is more than that of Iguanodon. Iguanodon mainly lived from the late Jurassic to the early Cretaceous, while hadrosaurs were found on land in the late Cretaceous. Among the Iguanodons, the most famous one is Iguanodon, which is mentioned many times in the chapter of dinosaur discovery history in this book. Here, we only focus on what dinosaur experts know about it now. It is about 10 meter long and about 5 meters high. Its forelimbs and shoulder blades are relatively large and heavy, and its nail-like thumb is its main feature. It has four fingers on its hand, and the fourth finger is almost at right angles to the wrist bone, so it can be used to hook branches. Its fingers are not only used for grabbing food and self-defense, but also for keeping the body stable when walking. This hand structure, together with its long neck and tail, and the ossified tendon extending from the scapula to the middle of the tail, make it walk or run very smoothly and quickly, with an average of 35 kilometers per hour. It has thick hind legs, three toes on its feet, toes and claws like hooves. Its head is very big, much like today's horse's head, with a horny beak, no teeth in the front of the upper and lower jaws, and serrations on both sides of the rear teeth. Bite each other. Iguanodon got its name from its lizard-like teeth. Iguanodon was found in Europe, North America, North Africa and ancient Mongolia, but only sporadic bones and footprints were found in China. According to a large number of discoveries of Iguanodon fossils, experts think it is gregarious. The most primitive Iguanodon is the curved dragon. It also lived from the late Jurassic to the early Cretaceous. It is 5 ~ 7 meters long, with short forelimbs and long hind limbs. It basically walks on two hind legs and can walk on all fours when eating low plants. Its forelimbs have five fingers, but it doesn't have a fingernail-like thumb like Iguanodon. The hind limb has four toes, and both the front and rear limbs have hoof-shaped fingers (toes). Its femur (thigh bone) is curved, so it is called curved dragon, and its Latin name means curved lizard. Its skull is very small, the front hole of the skull is degenerated, with a horny beak, no teeth in the front of the upper and lower jaws, and lizard-like teeth in the back. The tooth is leaflike, indicating that it eats plants. With powerful hind legs and a tail that can keep the body balanced, Qulong can run very fast. Since it has no defensive weapons, the only way to meet the enemy is to run away.
hadrosaur
The hadrosaur fossils include many intact bones, egg fossils and footprints, as well as two mummies and undamaged skin on mummies found in Canada. Duckbilled dinosaurs were at the peak of the development of bipedal dinosaurs, with a large number, accounting for about 75% of herbivorous dinosaurs. Hadrosaurs lived in the late Cretaceous, which was a turbulent period in the history of the earth. The land area is constantly expanding, and there are low-lying swamps and lakes everywhere. At this time, the really flowering angiosperms appeared, and the fragrance floated all year round. In addition to typical Mesozoic plant communities such as cycads, conifers, ginkgo biloba and some ferns, deciduous trees such as magnolia, willow, birch and oak also appeared. Angiosperms began to crowd out gymnosperms and occupy a dominant position, some of which have modern characteristics. This natural environment is especially suitable for the great development of vegetarian dinosaurs, among which hadrosaurs are a large category. So they are called hadrosaurs, mainly because their skulls and the front of mandibles extend forward to form a flat and wide mouth with a horny beak in front, which is very similar to the mouth of ducks. Their skulls are higher and their eyes are at the back, similar to modern horses and cows. They have a pair of big eyes with sclera plates around them, which can move up each other. They have a large optic nerve, so they have good eyesight and can keep a high degree of vigilance against carnivorous dinosaurs. One of the main characteristics of hadrosaurs is that there are teeth on the upper, lower, left and right sides of the jaw, and each tooth bed can have up to 500 teeth, so this dinosaur has up to 2000 teeth. Their teeth are prismatic and alternately arranged in tiles, and their teeth have washboard-like grinding surfaces. Old teeth are polished and new teeth grow to supplement them. In the stomachs of two hadrosaurs, researchers found needles, twigs of conifers (such as conifers and cypresses), seeds of angiosperms or other hard fragments, which were very hard. The above characteristics of hadrosaur teeth are the result of long-term adaptation to these foods. Hadrosaurs are usually 7 ~ 15 meters long. They mainly walk on hind limbs, and their forelimbs are small and slender, like a pair of "little hands". Their tails are flat and powerful, which can keep their bodies balanced. The toes of the hind limbs degenerate, leaving only three toes, and there are hoof-like claws at the ends of the toes. The thumb of the forelimb disappears, the second and third fingers have hoof claws, the fourth finger has no claws, and the fifth finger is very small. The shape of the foot is very similar to that of Iguanodon, which can make the hadrosaurs walk smoothly. The biggest feature of hadrosaurs is the specialization of skulls. Some are flat-headed, without special decoration, and some are crowned. People call this kind of protrusion with different shapes the top decoration. It is formed by the nasal bone or frontal bone of the head, and the air entering from the nostril has to go around in the top decoration, and then enter the trachea and lungs, so the difference between the hadrosaurs is mainly in the top decoration. According to whether there is a crown or not, we divide the hadrosaurs into two subfamilies. Those without crowns are called Cymbinae, and those with different crowns are called Langlongyinae, in memory of Canadian paleontologist Lamby. In addition to the crest, these two different subfamilies are also different on the pelvis. Members of Ranunculaceae have large plate-like protrusions on their ischium, wider pubic bone and hooked protrusions at the lower end, but dinosaurs of Cymbinae do not have these characteristics. The most interesting thing is the function of the top decoration of Ranunculaceae plants. Although there are many opinions on this point, none of them are satisfactory so far. For example, some people used to think it was used for fighting, but the bones of the top decoration are very thin and obviously cannot be used as weapons; Some people say that it is used for gas storage, but in fact, there are not many gas storage in the top decoration; Some people think that there are male dinosaurs with crowns and female dinosaurs without crowns. But these fossils are found in different strata, which is obviously not the difference between male and female. Recently, many people think that the crown is a signal to distinguish different sexes or different kinds, and it is also essential for communication between the same species. For example, the decoration on the top can be used as a * * * sound box to know and call partners through sound. If this statement is true, it is conceivable that the open space in the late Cretaceous was once filled with the noise of such dinosaurs. Among dinosaurs without top ornaments, the most famous one is the giant Shandong Dragon found in China, which we will introduce in detail in the next chapter. Among the uncovered hadrosaurs found abroad, the most famous one is Edmonton dragon found in Red Deer Valley, Alberta, Canada. Edmonton dragon. Edmonton is a city name. This dinosaur is 13 meters long and weighs 5 tons. It has a short and tall skull, a slightly inclined face, a flat and wide mouth like a duck, and there are about 1000 teeth in it. Because the needle was found in its stomach, people thought it lived in a dark and humid cypress forest. There is also a dinosaur called hadrosaur, which is also a hadrosaur without a top decoration. It is huge, and its length can reach more than 12 meters, even longer than three cars. The mouth and nose occupy half of the flat skull, and there are thousands of teeth in the mouth. It has developed visual and auditory organs. Although there is no top decoration, there are cheek pouches on the side of the face, which can also make sounds. The footprints it left tell people that this hadrosaur is also gregarious. There is a good name called Yalong, because it looks like a huge duck. This dinosaur was also found in North America. The crested hadrosaurs can be represented by spinosaurus. The Latin meaning similar to Spinosaurus is a reptile with a parallel crown. On the head of the male Spinosaurus, there is a top ornament made of a long tube protruding backwards. On the head of this spinosaurus, there is a top ornament made of a long tube protruding backwards. This top ornament can be as long as1.8m, which is longer than that of ordinary adults in China. If you dissect the top decoration, you can see that it consists of four long tubes, two upward and two downward. When it exhales, the airflow vibrates and makes a sound, which is convenient for dinosaurs of the same species to recognize each other and can also give an alarm to their companions. Judging from the discovered spinosaurus fossils, the top ornamentation of adult males is larger than that of females. Spinosaurus lived in Alberta, Canada and the United States. There are many kinds of top ornaments of dinosaurs of the subfamily Wollonginae. For example, the top decoration of Langlong is square, pointing forward; The crest of the helmet dragon is tall and narrow, and it grows on the top of the head.
Lesotho dragon
In the early Jurassic period 200 million years ago, ornithopods were also a very active dinosaur team. Lesotho dragon found in South Africa is one of the important representatives. The exquisite Lesotho dragon is less than 1 meter long and weighs less than 10 kg. Its mouth is covered with keratin, which can help cut off plants. Then, teeth with different shapes in the mouth can handle these foods. The teeth on both sides of the jaw are arrow-shaped, which is very suitable for biting food. Although Lesotho dragons are small in size, the good balance of their body structure ensures their agility, so they can still adapt and live well in an environment with limited resources and always lurking predator crisis.
Huayanglong-the earliest stegosaurus in China
Similar to sauropods, stegosaurus may have appeared in the early Jurassic. However, scientists' understanding of the early Stegosaurus actually began with Huayang Dragon unearthed in Dashanpu, Zigong, Sichuan, China. Huayanglong is nearly 4 meters long and weighs 1 to 4 tons. Compared with the Shu Dragon, the Chief Dragon and the Emei Dragon, which lived in the same era and region, Huayang Dragon is really too short and too small. Therefore, when those big guys raise their necks and munch on the leaves on the tall trees, Huayanglong can only eat low plants near the ground. The relatively short body of Huayanglosaurus seems to be more likely to be the prey of carnivorous dinosaurs such as Qilong. However, as the earliest stegosaurus, Huayang Dragon has developed a unique set of defensive weapons, that is, the long spines on its shoulders, waist and tail tip. When the Hungry Dragon attacks the life of Huayang Dragon, Huayang Dragon will turn its body to a proper position and let its long thorn point at the attacker; At the same time, beat the enemy violently with a spiny tail. Although these weapons and such defense methods are not enough to kill large predators, they are usually enough to have a deterrent effect, so that those predators can stop chasing Huayanglosaurus and look for prey that is easier to catch in order to avoid injury. At that time in the middle of Jurassic, rivers were usually covered with short ferns as dense as green carpets, and there were generally no tall trees in such places. When Huayanglosaurus forages on such an open "grassland" with small teeth suitable for gnawing, its larvae often become the coveted objects of predators such as riding dragons. However, as long as the young Huayang dragons are close to their parents, those predators still dare not attack easily. Obviously, it is essential for Huayanglong that parents protect their offspring's parent-child behavior. On the back of Huayang Dragon, there are two symmetrical rows of heart-shaped sword boards from neck to tail. Later, many stegosaurus had two rows of sword boards on each side of their backs. In addition, the front and rear legs of Huayang Dragon are almost the same length, while the front legs of Stegosaurus in the later stage are obviously shorter than the rear legs. These characteristics show that Huayang Dragon is really a primitive stegosaurus.