dinosaur
it is an old and novel term. It is said to be "ancient" because the dinosaur fossils we study are often hundreds of millions of years, tens of millions of years, and even the units are counted in millions of years; the "novelty" is because the word "dinosaur" was not created until 1841, less than 200 years, but in this short period of time, it contains a large number of new discoveries, and in recent years, dinosaur research has made rapid progress, and new theories have emerged in an endless stream, almost subverting all people's previous understanding of dinosaurs.
The dinosaur family is extremely large, with more than 800 genera having been discovered, which may account for only 1/10 of all genera. It stands to reason that fossils of paleontology with such a large and flourishing population should have been discovered long ago, but it was not until the 19th century that people really began to understand dinosaurs. The reason for this may be that, on the one hand, the dinosaurs are so large that their fossils are few complete after excavation; on the other hand, people may not have imagined that such a huge animal individual has ever appeared on the earth.
In 1824, the British mineralogist William Buckland named Megalodon based on a fossil of a vertebrate mandible.
Megalodon
It was also the earliest dinosaur to be named. Buckland described: "It is neither a crocodile nor a lizard, it is more than 10 meters long, far larger than a normal lizard, and the size is equivalent to a 7-foot-tall elephant." "The earliest dinosaur to be discovered was Iguanodon.
iguanodon
In March 1822, Anning, the wife of Dr. Mantel in the small town of Louis, England, found iguanodon fossils from a pile of ore containing small bones sent by miners at the Chickfeld-Tilgate Forest Mine.
After the unprecedented research of Mantel and Buckland, people began to demystify dinosaurs little by little. On 30 July 1841, the British paleontologist Sir Owen named this strange animal "Dinosauria" in a speech in Plymouth, and in 1842 it was first written in the book "British Fossil Reptiles". The word is derived from the Greek words "deinos" (huge, terrifying) and "Sauros" (reptiles similar to lizards). Owen also added a footnote to British Fossil Reptiles – "fearfullygeeat a lizard," meaning "very huge lizar kick." Thus, Owen's original intention may have been to describe a huge, awe-inspiring animal, rather than the "terrible lizard" (terrifying lizard" as explained in many dictionaries.
The word "Dinosaufa" quickly spread around the world, and in the East it was first introduced by the Japanese. In Japanese, the word was originally translated as "childophobia" and "dinosaur", representing two academic schools. The leaders of these two factions are Professor Yasujiro Yokoyama and Professor Takashi Iijima of the Faculty of Science at Tokyo Imperial University. At the end of the 19th century, both of them returned from studying in Germany, and both focused on paleontological research. The debate among Japanese scholars over the naming of dinosaurs did not end until after World War II. Professor Arakawa of the Faculty of Letters of Shizuoka University pointed out in works such as "The Origin of Ryu": "The lizard is too poor and weak, and Ryu gives people more psychological shock, so the translation of 'fear' is more appropriate." Later, the word "dinosaur" spread to China, and Mr. Zhang Hongzhao translated it as "dinosaur", and "dinosaur" was called out in China.
With the development of dinosaur science to this day, the definition of "dinosaur" has changed substantially, and it is far from the dinosaur in Owen's eyes. First, dinosaurs appeared in the Late Triassic of the Mesozoic Era, 21.3 billion years ago.
Late Triassic
It took nearly 160 million years until the Late Cretaceous extinction 65 million years ago that it became the most successful species ever lived on Earth. Secondly, dinosaurs are reptiles living on land, while contemporaries such as pterosaurs and marine reptiles occupy the sky and ocean, and they are distant neighbors of dinosaurs. Dinosaurs were widespread on all continents and occupied all ecological zones. Dinosaur fossils are abundant in almost every corner of the world (including the Arctic and Antarctic), especially in western North America, the Gobi Desert in Central Asia, and the Patagonian Plateau in Argentina in South America. Again, the limbs of the dinosaur are directly below the body, swinging on the plane in the anterior and posterior directions, with a completely upright posture; the bone disc is completely vertical; the acetabulum is perforated, the upper edge bears the weight of the body, and the expansion becomes a bone edge ornament, supporting the femur (commonly known as the thigh bone).
In terms of taxonomy, after Owen coined the term "dinosaur", in 1872, Schiller divided dinosaurs into two categories based on differences in the structure of the dinosaur belt (commonly known as the pelvis): Saurischia and Omlthischia. The former has a lizard-like three-shot belt, while the latter has a four-shot belt similar to that of a bird. Later, the sauropods were divided into sauropods and theropods, and the ornithischidae were divided into ornithopods, swollen-headed dragons, horned dragons, stegosaurs, and ankylosaurs.
The Triassic is the first epoch of the dinosaur age, dating from 25.1 billion to 199 million years ago, lasting about 52 million years. In the Late Triassic, the Earth's climate transitioned from drought to humid heat, when the earliest dinosaurs appeared, the first robbers.
The First Thief
First discovered in Argentina in 1993 , it was only 1 meter long and had a skull of only 12 centimeters , and was a bipedal theropod dinosaur with hind limbs. Although the First Thief still had five toes like its ancestors, the First Dragon, its fourth toe had degenerated, and the fifth toe only played a supporting role, relying only on the three toes in the middle of the paws to support the weight of the whole body when standing, a feature inherited by its theropod descendants. In the science fiction blockbuster "Jurassic Park", the famous Thief Andyrannosaurus and Tyrannosaurus are its descendants.
Dragon Raider
Dinosaurs that appeared in the same period as Archaeopteryx also include Herrera dragons,
Herrera Dragon
Southern Cross Dragon, etc.,
Southern Cross Dragon
They all live in South America. At this time, north American states lived in an unusually fierce carnivorous dinosaur, the coelentosaurus. This is a small and medium-sized carnivorous dinosaur, named after hollow bones and dexterous bodies. They often moved in groups or small groups, much like today's wolves. Their staple diet is a number of small mammals , which may also attack larger plant-eating prosauropods. In 1972, American Colbert found hundreds of coelentosaur remains at ghost ranches in neighboring New Mexico. The discoverers believe they were likely to have died in floods caused by heavy rains and were buried by floods. Among them, the most striking are several fossil specimens of small cavity bone dragons in the body. The discovery initially led some to speculate that the dinosaurs were oviparous. But now ^ we think that in some cases, coelentosaurs are a cannibalistic animal.
The earliest plant-feeding dinosaurs are thought to be Pisanosus,
Pisanolong
But there is still controversy about this. The most famous of the early plant-eating dinosaurs were European rhymingosaurs and African vultures
Vultures
and the Asian Lu Feng Dragon,
Lu Feng Long
They are 5 to 8 meters long, belong to the protosauropods, and were once thought to be the precursors of The Jurassic sauropods.
The Jurassic is the second epoch of the Dinosaur Age, dating from 199 million to 145 million years ago, lasting about 54 million years. During this period, dinosaurs finally became the rulers of the land, pterosaurs
pterosaur
and Archaeopteryx
Archaeopteryx
It also began to appear. The dinosaurs who lived during this period began to go to extremes——— and the size of some kinds of dinosaurs became crazy like balloons. From the Jurassic body length of 18 meters of whale dragons, 20 meters of Emei dragon, brachiosaurus, dome dragon, 26 meters of Mamenxi dragon, confused dragon (Thunder Dragon), 27 meters of Chuanjie dragon, Liang dragon, 30 meters of earthquake dragon, to the Cretaceous body length of 12 meters Amagalong, Salta dragon, 20 meters of dragon, 30 meters of Poseidon dragon, 40 meters of Argentine dragon
Argentinosaurus
...... These huge guys are the sauropods we know as the long-necked, long-tailed sauropods. This taxon began to diverge from the day of its birth - Emei dragons evolved tail hammers, beam dragons grew whip-shaped long tails, Amagarons grew two rows of long mane-shaped spines on their necks, and dragons and Salta dragons were draped with small bony decks (these rounded decks were scattered on the surface of the body and played a good protective role)...
At the same time, the nemesis of these behemoths also followed - Antarctica's ice ridge dragon with two small horned cones on its head,
Ice Ridge Dragon
The Head of the Americas is a diplodocus with two ridged crowns,
Diplodocus
Asia's univertebrates, air dragons, Yongchuan dragons, Chinese raptors, and Allosaurus throughout the Americas, Africa, Australia and Asia. These ferocious hunters, who look much the same, are small hands and feet, and the blood basin mouth is densely packed with dozens of dagger-like teeth with serrated edges, and the teeth are sharp and bloodletting grooves. It's not hard to imagine the tragic and bloody scenes of them strangling sauropods.
By the early and middle Jurassic periods, stegosaurus had embarked on the stage of life history on Earth. The earliest appearance is the Huayang Dragon in Sichuan, China,
Huayang Dragon
They are typically characterized by the bone plates of the back, arranged sequentially from the neck to the caudal end, with four sharp tail spines at the end of the tail and a pair of large shoulder spines on the shoulders. There is also the stegosaurus class, typically the American late Jurassic stegosaurus, whose back bone plate is abnormally large, perhaps having the effect of defense, attack and temperature regulation (although recently, the theory that bone plates have the effect of regulating the body temperature of dinosaurs has been almost denied). The organization of the stegosaurus bone plate shows that its bone plate evolved only for defense, and its structure is the same as that of ankylosaurs, turtles, armadillo shells, and even fish scales. The armor covered by modern armadillos is composed of many small pieces of bone, each of which also has a layer of scales, thus becoming a protective shell for armadillos to resist enemies. In terms of structure, the bone plate of stegosaurus is not much different from the tiny bone fragment of an armadillo.
Cretaceous
It is the last epoch of the Dinosaur Age, dating from 145 million to 0.65 billion years, which lasted for about 80 million years. The dinosaur family reached its peak during the Cretaceous period, and its variety is greater than that of the first two epochs combined. At the same time, ancient birds continued to evolve, angiosperms arose in the Early Cretaceous, and the earth finally bid farewell to the monotonous green and brown, and began to be draped in thousands of purples and reds. The Early Cretaceous was an era of biological transformation: dinosaurs began to reach the end of madness; modern reptiles—crocodiles, snakes, lizards, and turtles and turtles shrunk in their shells—were already formed; new birds soared into the sky; and timid and warm mammals began to grow and challenge dinosaurs, paving the way for their future dominance.
In this era of beauty, the most unwilling to be lonely are some small and medium-sized theropod dinosaurs, including sickle-wielding claws, unjustly egg-stealing dragons, toothless bird-like dragons, as well as robbers and dinosaurs. Dragons and dinosaurs belong to the chi-dragon class,
It was a small bipedal carnivorous dinosaur with a light body structure, a light skull, large orbits and anterior orbital foramen, flattened teeth, and small serrations on the anterior and posterior margins. The greatest feature of the chiliosaurs is a long, straight tail with a tightly joined tail vertebrae and surrounded by elongated, ossified tendons, forming a rod-like tail. The long tail of the chilong was once thought to have a balancing effect, but now some studies believe that the long tail can only be swung up and down, and its role is to save energy, which is conducive to the running of the chilong.
Early on , paleontologists Turner , Markvich , and Norrell claimed that they had found a feathered structure in the forearm ( ulna ) of a fossil of a Mongolian " Spira triatophyllosaur " , which was direct evidence of the feathers of " Apatosaurus " .
A feather nodule is where the secondary feathers are attached to the stem and are fixed to the bone by ligaments. Most living birds have a feather nodule structure, most notably the able-bodied flyers among the birds, while those that have completely lost the ability to fly usually do not have a feather nodule structure.
This dragon may have been 1.5 meters long and weighed about 15 kilograms when it was alive. Comparing Apatosaurus with living birds, in any way, Apatosaurus was not capable of flying. It seems that the ancestors of the dragon have lost their ability to fly, but still retain feathers, which are useful for showing off, protecting the nest, regulating body temperature, and assisting in control when running.
In western Liaoning, China, following the first discovery of hairy dinosaurs in 1996, the Chinese dragon bird of the "Jawed Dragon" species has been successively discovered.
Chinese Dragon Bird
The primitive ancestors of the bonyosaurs, the tail-feathered dragons of the oviraptorosaurs, the northern tickets of the sickle-like dragons, the Chinese birds of the Chilong class, and the small pirates. Among them, the Chinese dragon bird has a very primitive feather structure, the tail feathers and the feathers of the small pirate dragon are very similar to the bird feathers, and the chilong species may represent the closest to the birds - the dinosaurs - imagine these dinosaurs about 1.5 meters long in the sky wearing colorful feathers, how gorgeous it should be!
There are also important discoveries such as arboreal life, four-winged thief and foot-feathered dragon.
Foot feather dragon
The latter two have long feathers attached to their hind limbs, as if adding two wings, and are known as "dinosaurs with four wings". The furry Tyrannosaurus, which was about 116 meters long, proved that the early ancestors of the tyrannosaurs were small, and then slowly evolved to 13 meters long. Later Tyrannosaurus rexes gradually disappeared with increasing body size and growing scaled nodules. It is also interesting to find a fossil of a sleeping dragon in the early years, the hind limbs of the dragon curled up under the body, the head buried under the forelimbs, very similar to the current sleep state of birds, this is the first time to find a dinosaur fossil that was sleeping before death.
The large theropod dinosaurs of the Cretaceous are represented by the "Four Killers", which are the North American Tyrannosaurus rexes
tyrannosaurus
The lengths of Asian Tyrannosaurus rexes, South American megalopods and African spinosaurs were 12.5 m, 11 m, 14.5 m and 12 m, respectively. Not only did they inherit the full mantle of the Jurassic carnivorous dinosaurs, but they also went to extremes, such as the teeth of tyrannosaurs that were 20 centimeters long each, and the back of spinosaurs supported a bone sail, which grew from the spinous bone and was supported by a series of long spiny columns.
The food that is reduced to food is generally ornithopods, which is also an extremely large taxon, of which the aforementioned iguanodons are one of its members. The earliest ornithopods appeared in Early Jurassic Africa, including Lesotholus and Allodonosaurus. Ornithopods lived in groups, the most famous of which was the duck-billed dragons.
They have diamond-shaped teeth in their mouths, which make up the tooth plate, and the number of teeth on the upper and lower jaw teeth plate can reach more than 2,000. There are several ornithopod dinosaurs with quite peculiar shapes, such as the parachuteple with a horn on its head, the Lai's dragon with a flattened crown and a teapot shape, the Qingdao dragon with a vertical flute in its head, the crowned dragon wearing a helmet, and the loving mother dragon that will raise offspring, and so on.
Despite the ferocity of the "Four Killers", there are still several types of plant-eating dinosaurs that are stubbornly resisting, the most famous of which is the horned dragon. In many film and television works, the duel scene between the Triceratops and the Tyrannosaurus has long become a classic. Horned dragons lived in groups, somewhat similar to the bison of modern Africa. The naming of horned dragons is mostly due to the shape and number of horns, such as small horned dragons, slender horned dragons, weak horned dragons, sharp horned dragons, haloptera, short-horned dragons, open-horned dragons, ox-horned dragons, unicorns, diplodocus, triceratops, and pentagrams.
Pentagonal
Plant-eating dinosaurs that resisted stubbornly included ankylosaurs. In terms of self-defense, ankylosaurs have reached their apex, and they are covered with solid bone plates and sharp spines, of which the noduleosaur family does not have a tail hammer, and the ankylosaurus family has a expanded bone tail hammer.
In his study of its decks, Dr. Schayer of the University of Bonn in Germany found that these decks have complex microscopic tissues that are made up of countless collagens in 3D patterns. Collagen, also known as collagen, is structured like a rope and is composed of three "polypeptide chains". If these collagens are turned into aramid fibers, they become the "bulletproof vests" they are now! Such a bulletproof vest is not only lightweight, but also has good flexibility, and its structure can absorb the energy of the impact and disperse it to other fibers, avoiding "blunt injuries" to the greatest extent.
The last fighter of the plant-eating dinosaurs is the swollen-headed dinosaur, a brand new plant-eating dinosaur, whose head is covered with bone plates about 20 centimeters thick, and their faces are decorated with spines with bone protrusions, which look hideous. This skull structure favors it as a winner in a fight against foreign enemies or courtship.
The current mainstream view is that 65 million years ago, when dinosaurs were striding across the continent with their heads up, extraterrestrial meteorites brought a catastrophe to the entire ecosystem of the earth.
The vast majority of dinosaurs slowly went extinct over the centuries that followed, but one of them may have evolved into a winged bird to survive. In fact, the most fascinating thing about dinosaurs is not their extinction, but the long time they dominated the earth – about 160 million years! For such a long time, dinosaurs have left us with too many mysteries: a large number of missing links in evolution, the mystery of extinction, the controversy of blood and cold blood, the mystery of the origin of feathers, the mystery of flight...
The traditional view is that dinosaurs are a group of giddy, slow-moving ancient reptiles, and in the past 20 years, a new generation of dinosaur scholars have appeared to "resurrect" dinosaurs with new thinking and new methods, causing a revolution in dinosaur research and setting off today's public enthusiasm for dinosaurs. From a series of new studies, dinosaurs are no longer stupid guys, but flexible, intelligent animals, some of which still have higher metabolism of warm-blooded animals. What's more, in a sense, dinosaurs didn't go extinct, they still flew in the skies of today's Earth!