Flying dragons are in the sky, while hidden dragons are lurking in the water.
The word dinosaur was put forward by British anatomical paleontologist richard owen in 1842. This is based on the Greek prefix deinos, which means fear of cloth; And the suffix sauros, which means lizard. This glossary shows different symbols and pronunciations of different national languages. The most interesting thing is that a Kikuyu asked inexplicably, how can we name something that we don't fully know whether it exists or not? So there is no word "dinosaur" in Kikuyu!
What exactly is a dinosaur? Scientifically, dinosaurs must be defined as an evolutionary concept. It must include all animals that inherit their offspring through the earliest same ancestor type. Because the fossil record is incomplete, we may never find and determine who the true ancestors of all dinosaurs are; However, all members of this group can be identified by identifying the unique features they obtained from the earliest dinosaurs. In genealogical classification, the characteristics derived from dinosaurs are closely related to their migration patterns: (1) The hind legs are located directly below the body, swinging back and forth on the plane, and completely upright; (2) The pelvis is completely vertical; (3) The upper edge of acetabulum bears the weight of the body, expands the edge ornament of osteogenesis, and supports the femur. Therefore, the two most critical features derived from dinosaurs are: there is a central hole in the acetabular fossa; There is an enlarged bone margin above the acetabulum.
Flying dragons are in the sky, pterosaurs are not dinosaurs. Soaring in the sky, carefree, they are the closest neighbors to dinosaurs in the Zulong group! The fourth finger of the forelimb extends to support the wing membrane; They are the masters of the Mesozoic sky. Almost at the same time as dinosaurs, they stepped onto the stage of evolution and ended the catastrophe of extinction together at almost the same time. Only pterosaurs, a branch, left no descendants and walked into the ashes of history. We don't know how they fly or walk Is it really like a skier, clumsily and strangely running a sled?
Dragons are in the water, ichthyosaurs, plesiosaurs, dragons, black dragon ... they are not dinosaurs. Swimming in the waters of the ocean and drifting with the current, they are a group of amphipods in the chorionic fauna and distant relatives of dinosaurs. Adapting to the habit of swimming and developing fin-like appendages and streamlined bodies like fish is also the end point of convergent adaptation's evolution.
Returning to the sea, the first night of Jin Daban: the birth of sheep eggs is the key to the success of Normandy landing expedition. The water-loving plot, which is hard to give up, forced these reptiles to return to the water and develop pulp appendages suitable for parade. Zhonglong is not a dinosaur, but a witness to plate drift. In Gondwana waters 280 million years ago, Zhonglong left a fossil legacy. The drift of the plate made loong, once a neighbor, spread in South Africa, South America, Australia and Antarctica. The keen Wagner reassembled scattered fragments and put forward an excellent theory of continental drift, and Zhonglong is undoubtedly the witness of plate drift.
Gradual change of dynasty
There are kings in Jiangshan generation, each leading the way for hundreds of millions of years. The impermanence of imperial dynasties and the pulsation of terrestrial vertebrates are our focus. Throughout the history of terrestrial life, the evolution and development of pioneers and their ultimate fate are the key to understand the true position of dinosaurs in this big network: the first dynasty was primitive reptiles and amphibians in Carboniferous and early Permian; The second dynasty was the predecessor of theropoda, like mammals and reptiles; In the third dynasty, dinosaurs dominated the earth; The fourth dynasty, on the other hand, gave glory to mammals, our distant relatives and close neighbors. Set the stage, and the show will begin; As a link between the past and the future, dinosaurs stepped onto the stage of evolution and played an omnipotent arrogant role.
The mystery of the rise and extinction of dinosaurs is an eternal unsolved case. Success or failure heroes, take a walk, are they good (good genes)? Lucky (lucky)? They suddenly walked off the stage and the prisoners cried. Is it discomfort (genetic difference)? Or misfortune (bad luck)? What about Darwin's theory of natural selection and the hard struggle of wedge embedding? Fossil record, witness of striding towards extinction, don't you think? Disasters always depend on each other, and yin and yang must be born; The extinction event before the end of Triassic opened an opportunity for dinosaurs; Another mass extinction event at the end of Cretaceous rang the late bell. Success is death, failure is death, accident or fate? Mysterious nature!
Extinction is the fate of all life. The fossil record of nearly 600 million years in the history of the earth shows five extinctions, and life forms and groups have been reshuffled. With copper as a mirror, you can be well dressed; Taking history as a mirror, we can know the rise and fall. Scientists are still not completely sure about the mass extinction event 65 million years ago. Is it the killer of meteorite/comet rain that caused the fireball in outer space? Or did Deccan growl endlessly and spew out volcanic ash that covered the sky? The catastrophe is vivid; The bones are cold and the evidence is placed; Interpretation means that scientists tell a story as reasonably as possible.
If the light rain didn't hit my head, the curious baby asked, what would happen to dinosaurs? Stimulate curiosity, lead imagination, build a big structure, children are the big future, this is really a key good question! There are 103 known iridium anomalies in the world, all pointing to criminals' killing weapons, namely comet rain/meteorites falling from the sky. The muzzle of the smoking gun points to the scar on the crater of Chisulubo, Mexico. 65 million years ago, if the "light rain" didn't hit me on the head, would evolution reproduce the drama code of rewinding and recreating life according to the same trajectory? Did dinosaurs that lived for10.6 billion years enlarge their ventricles, use tools or even make weapons? And the mammalian ancestors of our distant relatives and close neighbors, or are they committed to the best and drag out an ignoble existence in a huge shadow? 225 million years ago, Maniku Forrest Gump Crater in Quebec Province marked the opening of the dinosaur dynasty. 65 million years ago, chicxulub crater in Jugaton marked the end of the dinosaur dynasty. What should I do if the light rain doesn't hit me?
Is the egg thief incubating eggs?
The American Museum of Natural History and the Mongolian Academy of Sciences in new york made a survey and excavation in the Gobi Desert (1990- 1995), which was very fruitful. The fossil of the egg-stealing dragon is 2.5 meters long and was found crouching in the nest of more than 20 eggs. There were embryonic larvae in the broken eggs. Oviraptor, who restored the model, returned to the nest and ate with dragon larvae in his mouth, just like a live bird. Science has evolved, and the egg stealing dragon has become an incubating dragon. Paleontologists use clues and fragments to reconstruct the history of life, which is both interesting and fascinating!
Paleontologist Osborn named the egg dragon philoceratops in 1924. Its peculiar head has a beak like a bird, a horny sheath, no teeth in its mouth, only two bony protrusions. Is this used to crush eggshells? The truth can only be guessed, but the scene vividly depicts a furious protoceratops, returning to the nest and fighting back with the egg thief to the death. Scientists hold evidence in their left hand and imagination in their right hand, trying to construct one legend after another.
In the desert, the world of mortals is rolling, and the rain is turning over the clouds, covering the sky. The conscientious "egg-stealing dragon" stretched out his mother's warm arm to protect a hotbed of innocent children. 80 million years ago, the film was frozen, the eternal memory of life history; Fossils tell stories and anecdotes that gradually disappear in the lost world. Opponents touched the heartstrings of every curious child.
How did dinosaurs give birth to children?
A small step in the birth of eggshells is a key step in the evolution of vertebrates. Amniotes gave up the story of love for water for hundreds of millions of years, walked out of the water and established the first beachhead where Qilu lived. Born in the ocean, it cut the umbilical cord of the waves; The sea is still the mother of all life, and it is the homesickness of midnight dreams. Semi-permeable and mineralized eggshell, selective gas in and out, carefully care for the birth of life; All kinds of bags in amniotic bag provide a cradle for the development of life. I can't get rid of the eternal and vague memory of the sea. I carefully took one Wang Yang, wrapped them in the most intimate secret room, and skillfully transformed the original water world with shells outside the sea.
Look for bones in eggs, and see dinosaurs in bones. 1923, Andrews found the first nest of dinosaur eggs in the Gobi Desert, which broke the ground and solved the eternal unsolved problem of how dinosaurs gave birth. Half a century later, Ona uncovered another mystery of the mother dragon hatching eggs and giving birth in Longdan Mountain, Montana. The dinosaur took care of the baby. During the period of 1974, tens of thousands of dinosaur eggs were found in Xixia, China, which shocked China and foreign countries. Is this an egg laid by a dinosaur? Or a dinosaur nursery? Picky paleontologists pick bones in dragon eggs, and beautifully preserved bones tell the peaceful sleeping position of Kamakura embryos hundreds of millions of years ago; The appearance of sleeping position recovery reminds us of legends and anecdotes about how dinosaurs gave birth to children in that lost world.
Egg fossils of different shapes, sizes and patterns, how do we know who laid the eggs? Scientists really don't know that in addition to delicate eggs, there are small dinosaur embryos that are about to break out of their shells. The classification of eggs and dinosaurs are two parallel lines that are difficult to communicate: oogonidae, oogonidae, Polyodontidae and oogonidae, all of which are ingenious tricks. The mother dragon hatches eggs and gives birth; The egg-stealing dragon crouched on the nest egg, with its cold ass sticking to the egg, for what; How did a 40-meter sauropod dinosaur lay eggs? How to hatch eggs? Does Ankylosaurus hatch eggs? Does ceratosaurus hatch eggs? Does Tyrannosaurus Rex hatch eggs? A series of interesting and fascinating questions are waiting for you and me to answer!
Dinosaur's recipe feast
Food and sex are two major factors in evolution. How dinosaurs gave birth to children is the most fascinating topic; How dinosaurs filled their stomachs is the most complicated behavior and mechanism. Like all living animals, the bottom of dinosaur food chain is plant community and various plant-eating species and genera. These basic groups provide carnivores and scavengers, feeding in groups or preying on individual prey alone. The sun provides energy for plants; Plants provide energy for animals.
Darwin believed that ecological drama is a complicated and arranged plot, and it is a continuous struggle among competitors, predators and prey. The so-called "nature is full of bloody battles with sharp teeth and claws." But most dramas are rooted in the evolutionary relationship of daily interaction. In order to grab and handle their daily food feast, some dinosaurs developed extremely special equipment, such as grasping forelimbs, swinging claws, teeth for grinding food, and even fermentation barrels for digesting a lot of fibrous food-that is, ribs propped up a big belly.
Dinosaurs found food in only two ways: eating plant salads or eating each other. Vegetarian, easy to get, difficult to operate and difficult to digest; Eating meat is easy to decompose and digest, but it is difficult to obtain. Brachiosaurus digested a ton of salad dinner with teeth and stomach stones every day; Hadrosaurs show amazing teeth, cheeks and jaw muscles of crushed and chewed plants; Ceratosaurus evolved a sharp, narrow beak and scissors-like tooth arrangement. Each of them has evolved different types of chewing strategies: sauropods are good at grabbing food; Hadrosaurs are equipped with special food handling devices; On the other hand, Ceratosaurus developed a special screening food.
The shape of the mouth often reveals the foraging strategy and adaptive evolution of dinosaurs. Ankylosaurus was a broad herbivore with a flat mouth. Small ornithopods with narrow mouths are meticulous food screening and specialized vegetarians; Egg-stealing dragon is good at bird's mouth. Is it really foraging eggs or shellfish? It is not known yet, but it is clear that their recipes are extremely special and carefully selected. Carnivorous dinosaurs had no regular ready-made food source. They developed deadly sharp teeth and hard jaws. Allosaurus attacked in small groups, preying on the living or dead bodies of groups of Diplodocus, Puzzled Dragons or Duckbilled Dragons. They are undoubtedly Mesozoic super hunting machines. Some scientists believe that Tyrannosaurus Rex is not a real predator, but a super scavenger dinosaur. This may involve the most fundamental question of large, carnivorous dinosaurs: Are they internal temperature type ("warm blood") or external temperature type ("cold blood")? So, should we eat more or less?
Do they eat meat or are they vegetarian? How do we know? Dinosaurs can be mainly divided into carnivorous theropods; Sauropods, ornithopods and herbivores. According to tooth morphology, tooth wear surface, jaw function, shape of corpse blueprint, chemical analysis of bone isotope, gastric residue, fecal fossils, sedimentary environment, etc., it can be reasonably inferred.
Descendants of the dragon, the hometown of the dragon.
Half a century ago, the first dinosaur excavated, studied and transformed by China people stood tall in Pei Bei, Chongqing. Xu's Lufenglong is about 6 meters long and stands as high as 3 meters. He is the father of China vertebrate paleontology. Academician Yang lives in Wayao Village, Kunming, and has made many achievements in cold and summer. Descendants of the Dragon opened a new field of dinosaur research. Dragon totem and dinosaur science parted ways from now on.
In the field of science and humanities, Lao Yang wrote a poem with great ambition: Ten million years ago, he was named Lu Fenglong of Xu Shi. Planting is limited to two continents, but it is short and ends in three folds. Re-creation is still remarkable, and the image should be muddy. Three hundred bones are recorded in one volume, and the payer studies similarities and differences. Grass flies, unrestrained, typical of the past.
China is the hometown of dragon phobia. The word "keel" first appeared in Huayang National Records of the Jin Dynasty (AD 265-3 17A). The keel excavated in Sichuan Province today is probably the fossil of Jurassic dinosaurs. The "dragon" is the auspicious beast in the ancient legends of China, and it is the totem of the whole civilization. Dragon totem has developed into the image of "horns like deer, head like camel, eyes like rabbits, neck like snakes, abdomen like salamanders, scales like carp, claws like eagles, palms like tigers and ears like cows". Puncture is attached to the prestige of imperial power, and keel and dragon teeth have become the focus of traditional Chinese medicine. After drinking the teeth of these horse fossils and the bones of mammals, China people have deeply believed that there will be a strong upward leap in five thousand years.
Sauropod dinosaurs, a dinosaur family distributed in all parts of China, are Mesozoic behemoths. Children's impression of dinosaurs is huge, slow, stupid and doomed to failure, mostly from the traditional concept of this group of dinosaurs. Are they really like this? From the earliest Jurassic sauropod dinosaur Lu Fenglong; For this petite Qiaolong in the Middle Jurassic, it is a relative of Camarasaurus and a juvenile larva. In the late Jurassic, the giant Emeilong was a relative of Liang Long. In the landscape of Jurassic Park, the branches and leaves are sparse and the business is abundant; Golden sunshine, sprinkled all over the earth. Emei dragons swarmed, calling friends, leisurely eating young leaves in the treetops, and the years were frozen in the mountains.
An elephant with a long nose; A dinosaur with a long neck. The elephant's nose wiggled deftly. Can the dinosaur's neck move freely? Still stiff? Are they holding their heads high? Or swing sideways? Just like a crane using the lever principle, the upper part is pulled by Zhang Chi, and the lower part bears pressure. The long neck of sauropod dinosaurs is a compromise between the principle of mechanical dynamic lever and the structure of segmented cervical vertebrae in vivo. Dorsal tension unit consists of muscle, tendon and tendon; The ventral incompressible cells are composed of mineralized bone or cartilage. Confused dragon (Lei Long) is a taut back and can move freely; Mamenxilong, Emeilong and Camarasaurus were all tense in their abdominal muscles, so they were born unable to swing freely. On the other hand, Liang Long has a double system with a long neck, but he can't move freely. Behavior, an interpretation in the structure of bone chain.
From the earliest Jurassic to the end of Cretaceous, Professor Dong Zhiming divided the dinosaurs in China into ten combination zones, marking the gradual replacement of dynasties:
(1) Lufenglong-Bian Shi Fauna [Lufenglong, Liang Long; The earliest Jurassic]
(2) Yunnanlong-China conodont assemblage zone [Early Jurassic]
(3) Shulong combination belt [Qiaolong, single-ridged dragon; Middle Jurassic]
(4) Emeilong-Chuanlong composite belt [Emeilong, Tuojianglong; Late Jurassic]
(5) Mamen Xilong-Yongchuan Dragon Combination Zone [Mamen Xilong, Yongchuan Dragon, Yandulong; Late Jurassic]
(6) Parrot-billed Dragon Combination Belt [Parrot-billed Dragon, Chinese Bird-like Dragon, Junggar Pterosaur; Early Cretaceous]
(7) Primitive Barkelon assemblage zone [Middle Cretaceous]
(8) Rod-shaped dragon combination belt [Asia is as ancient as bird dragon; Late Cretaceous]
(9) protoceratops combination belt [protoceratops, painted dragon, agile dragon; Late Cretaceous]
(10) Nanxionglong assemblage zone [Late Cretaceous]
In the special exhibition, except (2), (7) and (10), the other seven bands all have representative members. Nineteen dinosaur skeleton restoration specimens completely represent members of five families of two branches.
Dinosaurs are hairy and children are crazy.
Finding feathers in dinosaurs was once a dream of vertebrate paleontologists for many years. John H. orstrom searched the German Sorenhofen fossil treasure house and returned disappointed. Finally, I got my wish in distant western China.
Loong bird? Chinese bird dragon?
Confused the eyes of paleontologists all over the world, people saw the hope of feathered dinosaurs for the first time. Dinosaurs spread their wings and flew high! Make all the children crazy, make all the dinosaur experts panic. The appearance of Archaeopteryx and Tailfeather Dragon dealt a lasting blow. They are covered with real feathers, with shafts and branches. Feather is no longer the symbol and patent of "bird"! 1999, Xu Xing once again surprised the world.
Beipiaolong not only added a brand-new member to the long-haired dinosaur family, but also was covered with feathers. The continued publication of the Millennium Chinese Bird Dragon is not only the best preserved dragon group in the world, but also further preserves the more exquisite feather structure. Pentium, staggering; The Millennium Chinese bird dragon is undoubtedly the most perfect treasure that nature has given to the Millennium.
For a century and a half, the evidence of the origin and evolution of early birds is limited to one feather and seven fossil bones of Archaeopteryx. As well as sporadic fossils of quite advanced yellow-fainting birds and fish birds in the late Mesozoic. The case is too complicated and confusing; There is too little evidence at hand. There are 34 genera of birds in the early Mesozoic, more than half of which were found after 1990. Birds in China belong to 7 genera and play an important role. They embrace in the arms of Hou Lianhai, the authority of ancient birds in China, and dare not spread their wings and fly away again. Archaeopteryx, sage Confucius bird, petite Liaoxi bird, Boucher birch, Zheng Bo Luohong bird, Yan Dou Huaxia bird, six-toothed toucan and authentic fossils meet you.
Want to fly: everything is ready, just waiting for the east wind.
Flying is the unexpected ending of a series of accidents. Is that really the case? Haret (1984) described a series of dinosaur families, from running, preying, jumping to soaring. Flying, hanging upside down, is a test chain that flies through the tree, falls from the sky, glides and flaps its wings? Or get up from the ground and get out of trouble? National Geographic magazine (1998) describes the evolution of a series of wings, from dragons to birds, adding equipment, folding wrists, flapping ability, flying wings, controllable winglets and modern wings, which are all amazing. Flight conquered the last habitat of nature.
There are several important stages in the evolution of modern bird skeleton design and function. In view of the flight, many key and functional innovations in bones, in the early theropods, most of them were ulterior motives and other ways:
Neopoda (single-ridged dragon, double-ridged dragon): the skeleton is hollow, and the toe I that originally supported the weight has been removed.
New Synaptoptera (Yongchuan Dragon): The wrist joint can rotate freely, the forelimbs can be grasped properly, and the wishbone and black beak bones are developed.
Coracoid dragon (Chinese dragon): the coracoid bone develops with the sternum to prepare for the pectoral muscle; Warm first feather, long arm.
Apoptosaurus: Pioneer feather with a central axis, used for display and incubation.
Similar to birds (birds of prey): the trunk is tightened to enhance the stability of the coccyx as a function of balance and movement.
Birds (Archaeopteryx): flight and arboreal functions; Lateral shoulder joint, asymmetric wings, thumb varus.
Fan-tailed bird (Confucius bird): towering bony process, trunk-shaped black beak bone and coccyx.
Bird sternum (the first anti-bird): Trigeminal tubule is a wing rotator, winglet feathers control low-speed flight, rudder feathers completely reverse thumb grip.
Real bird (pigeon): elastic wishbone, towering keel sternum.
Meteorite-the terminator of dinosaurs?
65 million years ago, an unexpected event made many creatures that originally lived on land and sea go to history, and also made the giant dinosaurs that dominated the Mesozoic disappear on the earth stage. In the long history of the earth, the "K-T boundary" stratum between Cretaceous and Tertiary recorded this sudden and far-reaching meteorite impact event.
Scene 1:
Scientists infer that 65 million years ago, a huge meteorite with a diameter of 10 km hit the Yucatan Peninsula in Mexico today. The hypervelocity impact produced a strong explosion, causing trillions of tons of debris to rush into the atmosphere, and ash and smoke covered the sky for months, leading to the extinction of a large number of species around the world.
Scene 2:
An unusually high content of iridium was found in the clay layer of the K-T boundary in gubbio. In the process of earth differentiation, this high specific gravity element should stay in the core, which is rarely seen in the general crust, but it is abnormally enriched in the thin clay layer with a K-T boundary thickness of only about 1 cm. Scientists speculate that the high content of iridium may be the result of a huge meteorite falling. In fact, with the exception of Italy, the abnormal enrichment of iridium has been found in the K-T boundary layer on land and seabed all over the world.
Scene 3:
The Ocean Drilling Program (ODP) recorded this sudden event in detail in the deep-sea rock core 563 kilometers off the east coast of Florida, USA, and the tragic picture of the great disaster suffered by the global species after the impact. Before the incident, the ocean showed a vibrant and prosperous atmosphere, and then the species suddenly became extinct. After the incident, the remaining species slowly recovered and new species continued to multiply.
"Recent important meteorite impact events"
Tektite scattered in North America, Central Europe, Ivory Coast and Australia is a glass substance found on the surface. In recent decades, in order to verify the statement that "obsidian-like is caused by meteorite impact", scientists discovered craters near scattered areas in North America, Central Europe and Ivory Coast at that time. The rocks around the craters are closely related to the geochemical characteristics of obsidian-like in this area, which shows that obsidian-like is a glass substance formed by the high-speed impact of meteorites on the surface and the rapid cooling of surface materials.
Obsidian in North America is mainly distributed in Texas and Georgia in the United States, which was caused by impact 35 million years ago.
Moldovan rocks in Central Europe were formed in the collision event15 million years ago, mainly distributed in Czech Republic.
Obsidian rocks in Ivory Coast, Africa, are surface molten materials formed by meteorite collision1100000 years ago.
Australian obsidian, which was formed 700,000 years ago, starts from Leizhou Peninsula in China in the north, passes through Indochina Peninsula, the Philippines, Sumatra and Thailand, and reaches Australia in the south, covering about one tenth of the earth's surface.
The four major meteorite impacts mentioned above, although the global species will not change as much as an impact event related to the extinction of dinosaurs 65 million years ago, the scope of material splashing after the impact makes people feel scared of the situation at that time.
Over the mountains
"Truth" is the rosy clouds on the horizon, and "science" is another belief. Faith determines our view of nature, and nature is mysterious. With the continuous development of science, new evidence has triggered brand-new "explanations" and assumptions, and new thinking modes have been constructed. Popper's philosophy holds that there is no truth in science that can really be verified. Millions of observations cannot prove that a scientific conclusion is true, but one observation can prove that a scientific conclusion is false. Therefore, false propositions can be excluded from the scientific field, but "truth" is still being sought in unproven "speculation", sought-sought-sought-sought-sought.