Scientists have made the following explanations about how asteroids hit the earth and led to the extinction of dinosaurs.
Asteroids hit the earth quickly, causing drastic changes in the earth's environment. The huge impact throws a lot of rocks and dust into the air, which leads to frequent earthquakes, marine tsunamis and volcanic eruptions, and many forests are swallowed up by fires.
For decades, dust has been floating in the air, making it difficult for the earth to receive enough sunlight, so the number of plants has dropped sharply, leading to the collapse of the food chain from the bottom. At the same time, the weakening of sunlight makes the earth increasingly cold, and rainwater turns into hot acid rain mixed with volcanic eruption and falls to the surface, which leads to great challenges for the living environment of animals and plants.
Dinosaurs, which once ruled the earth for 65438+600 million years, could not adapt to the changes in the environment and were naturally eliminated. From black dragon and plesiosaurs living in the ocean, pterosaurs flying in the air to all kinds of dinosaurs living on land, no one was spared. In addition, many ancient creatures, including ammonites and marine plankton all over the ocean, were also extinct in this catastrophe.
Birds and mammals were badly hit, but they survived. Warm-blooded animals with long hair eventually replaced dinosaurs as masters of the earth, laying the foundation for the birth of mankind.
Supplement:
In the past, all scientists thought that dinosaurs were cold-blooded or warm-blooded like all reptiles, but with the increasing number of fossil data, people's understanding has also changed. Some people think that some dinosaurs may be warm-blooded animals. First of all, they think that some dinosaurs are extremely agile, and they don't crawl on the ground like snakes, but run on the ground with two hind legs, which can reach 20 to 90 kilometers per hour. This requires a strong heart and a high metabolism, which is obviously impossible for cold-blooded animals. Secondly, dinosaurs ate a lot. It is speculated that a 30-ton sauropod dinosaur may eat nearly 2 tons of food every day, and only warm-blooded animals need so much energy. This is also reasonable from the point of view that carnivorous dinosaurs are far less than herbivorous dinosaurs. In addition, there are some smaller dinosaurs, who are likely to be covered with a layer of feathers or hair, which is also to prevent the loss of body temperature. Other aspects, such as the study of bones, also preliminarily show that some dinosaurs were warm-blooded animals. As soon as the theory of warm-blooded dinosaurs was put forward, it was strongly criticized, but it is still difficult to reach a conclusion.
In ancient times, there used to be a group of strange creatures-dinosaurs. They ruled the earth, lived for nearly 15 thousand years, and finally died out magically. Everything we know about dinosaurs today comes from dinosaur fossils.
There are many kinds of dinosaurs, and their shapes and habits are quite different. Among them, the big one can be as big as dozens of elephants combined; Small, but almost like a chicken. As far as food habits are concerned, dinosaurs have mild vegetarians and fierce carnivores, and there are omnivorous dinosaurs that eat both vegetarian and vegetarian foods.
In addition, archaeopteryx also appeared with dinosaurs.
[Edit this paragraph] Discovered dinosaurs
The story of prout-Garon-Garon
Mrs Mantell found the story of dinosaurs really romantic. Mr Mantell was able to explore the ownership of dinosaurs with a rigorous and realistic attitude, which was indeed the first step for human beings to study dinosaurs scientifically and understand them.
But in history, humans have long discovered dinosaur fossils, but at that time, due to limited knowledge, they could not explain them correctly.
As early as 1000 years ago, during the Jin Dynasty in China, dinosaur fossils were discovered in Wucheng County, Sichuan Province. But people at that time did not know that it was the remains of dinosaurs, but regarded them as the bones left by the legendary dragons.
Based on the clues found in a historical novel "Mr. milken's Wife", a researcher named Huster at the University of Reading in England recently announced that he had finally discovered the following fact: 1677, an Englishman named prout-Garonne-Garonne wrote a natural history book about Oxford. In this book, prout Gallon Gallon describes a huge fossil leg bone found in a quarry in the parish of Karovilla. Prout-Garonne-Garonne drew a good illustration of this fossil, and pointed out that this thigh bone is neither cow's, horse's, nor elephant's, but belongs to a giant bigger than them.
Although prout-Garonne Province-Garonne Province didn't realize that this fossil was a dinosaur, or even associated it with reptiles, the specimen he described with words and illustrations has been identified by later paleontologists as the thigh bone of a dinosaur called Megalodon, and this fossil was discovered 145 years before Iguanodon was discovered in Mantels. Therefore, Hastert thinks that prout-Garonne-Garonne should be the first discoverer and recorder of dinosaur fossils.
In fact, the history of human discovering dinosaur fossils must have a long history. Long before Mantel and his wife discovered Iguanodon, Europeans knew that there were many grotesque huge bone fossils buried underground. However, people didn't know exactly where they belonged at that time, so they were always mistaken for "the remains of giants". As for China, as early as 2,000 years ago, we began to collect large ancient animal fossils unearthed underground for medicine, and called these fossils "keels". Who can be sure that the name "keel" has nothing to do with the discovery of dinosaur fossils?
The oldest reptile fossils can be traced back to the Paleozoic Pennsylvanian period (365,438+million years ago-275 million years ago). Tracing back to the source, it evolved from amphibians. Amphibian eggs need to develop in water. Reptiles evolved eggshells to prevent water from escaping. This major reform enables reptiles to survive without water.
By the Mesozoic era from 225 million years ago to 65 million years ago, reptiles had become the masters of the earth, so the Mesozoic era was also called the reptile era. Large reptile dinosaurs appeared in the early Mesozoic. Herbivorous Liang Long and Lei Long are the largest land animals. Tyrannosaurus rex is a carnivorous dinosaur. There are also ichthyosaurs living in the sea and pterosaurs living in the air.
Reptiles have multiplied on the earth for about 654.38+0.5 billion years. Among the animals of this era, dinosaurs are the most widely known. When people mention dinosaurs, they will see a huge and fierce animal. In fact, there are also small and docile dinosaurs among dinosaurs.
Dinosaur is a kind of vertebrate reptile, which was once produced in Mesozoic land swamp and had a long neck and tail. The hind limbs are longer than the forelimbs and have tails. Some of them are carnivorous, and some are herbivorous. They are huge and can be considered as the largest terrestrial animals. Its physique is similar to that of the oldest crocodile and beak in lower species, and slightly similar to that of birds in higher species.
The study of dinosaurs depends entirely on fossils. Paleontologists infer their shapes and habits from their fossils. According to paleontologists, dinosaurs are like living animals: there are big ones and small ones; Some people walk on two legs; Some people walk on four legs; Some eat plants, some eat animals; Some skin is smooth, and some skin has scales or bone plates. The similarity is that all dinosaurs have small brains and lay eggs on land (as do all reptiles).
[Edit this paragraph] Classification of dinosaurs
Early Cretaceous-Early Cretaceous-
Westerly Dragon (Westerly Dragon)
Xipo podeng
iguanodon
Mutabularon (Mutabularon)
Our dragon (fearless dragon)
Aquijubus (Aquijubus)
Aarti News (Aarti News)
Nanyang Dragon (Nanyang Dragon)
Ludelong
Connaron (Connaron)
Waldoro (dragon of the desert)
Fukui Ryong
Jinzhou dragon (Jinzhou dragon)
Tenontosaurus
The original Bacchus (Probactrosaurus)
Rellino dragon
Atlas dinosaur (Atlas dinosaur)
West Luo Long (West Luo Long)
Daryun (Australian Dragon)
Lightning beast dragon
Gerolone (Gerolone)
vertebrate
Xuanhualong
Stenopelix
Lin Long ()
Spinosaurus
Gaston Dragon (gaston Dragon)
Stegopelta (Stegopelta)
Tire hole
glyptodont
Armored dragon (Hoplitosaurus)
Polacanthids (Polypodiaceae)
Spinosaurus
Heavy armor (lizards)
Gobislon
Desert dragon
Mimi (Mimi)
Tianchilong
cedarpelta
Zunichella Topsy
Archaeoceratops (Archaeoceratops)
Chaoyang dragon (Chaoyang dragon)
Liaoning jiaolong
Hongshanlong (Hongshanlong)
Parrot dragon (parrot dragon)
psittacosaurus sinensis
P.meileyingensis, the parrot of meilaiying.
Ulron
Shengshanlong
Nu Luo Long (Nu Luo Long)
Ciobalon (Leah, Qiao Ba)
Super dinosaur
Asian dragon
Augustinia
Mongolian dragon (Mongolian dragon)
Niger dragon (Niger dragon)
Heath Terry Yalong of Isis
Leosolon (Leosolon)
Rebbachisarus.
Limalong (Limalong)
Amagat dragon
Amazon dragon
Pujin Gulong (Pujin Gulong)
Jiangshan Dragon (Jiangshan Dragon)
Chondrosaurus (Chondrosaurus)
Arago Dragon (arago Dragon)
Pelorosaurus (deformed dragon)
Australasian dragon (Australasian dragon)
Bird buttock disease (bird buttock disease)
Venetian dragon, an addict.
Astroden (Astroden)
Ocamerotes (Ocamerotes)
Pleural cavity (pleural cavity)
Sonorasaurus (Sonorasaurus)
sauroposeidon
Cedar dragon (Cedar dragon)
Gao Long (Aepisaurus)
Argos dragon (Argos dragon)
Clasmodosaurus (Clasmodosaurus)
Dragon (pterosaur)
Cube Tilong
Macron (Macron)
Don Huaron
Buwanlong (Phuwiangosaurus)
Tidal dragon (Paralititan)
Gobititan
Androsaurus (Androsaurus)
Malawian dragon
Altispinax
Squid (squid)
Capital dragon
Ba Long (Antarctic Dragon)
Yinlong
Jia He Long (Lulong)
Shengshanlong (Shengshanlong)
Wakinosarus (Wakinosarus)
Vogt E Long.
Kerma pterosaur (Kerma pterosaur)
Protodinosaur, a kind of protodinosaur
Spinosaurus
Ligabueino, small power.
Becks spinosaurus
Waldoraput
Homo erectus (Homo erectus)
Early Cretaceous-early Cretaceous
African dragon hunters
Tugulong (Tugulong)
Siamese dragon
Jiguanlong (Jiguanlong)
barite
Like E Long.
Angry person
The lofty dragon (Angaturama)
Fokila Ptor
Akron dragon (Akron dragon)
Dwarf dragon
New hunter
Ceratosaurus (ceratosaurus)
Giant dinosaurs in the south.
Bahamian dragon (Bahamian dragon)
Chilean dinosaur
Gun dragon
Birds like chrysanthemums.
Habibis looks like a bird.
Seven birds in seven towns
Agile dragon
Kakuru (color snake dragon)
Akron (Akron)
Nqwebasaurus (Nqwebasaurus)
Ned colbert
Santana laput
Scipio Knicks (Scipio Knicks)
Yaflandia (Yaflandia)
E Long ()
Sinosauropteryx (Sinosauropteryx)
Toona sinensis
Mei (Mei)
Mircia; Milicia
Protoarchaeopteryx
Timmy-like
Yixianlong (Yixianlong)
Small dragon hunting
Caudipteryx
Microraptor
Gu's Microraptor
Chinese bird dragon (Chinese bird dragon)
Tommy Tam (Tommy Tam)
Eotyrannus (dinosaur)
Siamese cat (siamese cat)
Tonuchiron
Curved teeth (China Curved teeth)
China is a dragon hunter.
paranasal sinus
archaeornithomus
Shenzhou Dragon (Shenzhou Dragon)
Trident dragon came from the mountains.
Pelecanimimus-like
Menodon
Ray Partor (Ray Partor)
Ornithodesmus (bird method)
Utahraptor
Deinonychus
Graciliraptor (Gracililaput)
Alashan dragon (Alashan dragon)
Beipiaolong
Geronis (Geronis)
Shenzhou elevator
Lucky bird
Sapphire (sapphire)
Jinzhou bird
Jan Dangol Nice (Jan Dangol Nice)
Confucius
Confucius bird
Confucius bird
C.chuanzhou Confucius bird
Sun Shi Confucius bird
Great Wall Bird (Great Wall Bird)
protozoan
Chinese bird
Huaxia bird
Chinese bird with tail
Longcheng Niaoyi (Longcheng Niaoyi)
Cuspirostorisornis(Cuspirostorisornis)
Large toucan
Long-winged bird
Bologna (Bologna)
Ji Bena (Ji Bena)
Liaoxi Hornus
Otto Gornis (Otto Gornis)
Protopterosaur (protopterosaur)
Liaoning bird
Chaoyang bird
Songling bird (Songling bird)
Yanonis (Yanonis)
Yixianniao
Long billed bird
Aberrationdontus (Aberration Dontus)
Ocean bird
-Late Cretaceous.-Late Cretaceous
Rat dragon (squirrel dragon)
Eutectic (eutectic)
Mivron
Newtonian dragon (Newtonian dragon)
Long-billed dragon (long-billed dragon)
Sidormimus
Sigmund Masas Dragon (Sigmund Masas Dragon)
Build canglong (build canglong)
Knee dragon
Joe (CompsoSuchus)
The wounded dragon
Genyodectes (Genyodectes)
Jabbar Pria (Pria, Dzubur)
Birch order (Birch order)
Muscle Dragon (iloc Les)
Zuo Fu is lighter than E Long.
Rugopus
Northwest Argentinean dragon (Noarosaurus)
Evil dragon
velociraptors
Raptors ()
E Long (Betassos)
Heterogeneous dinosaur (heterogeneous dinosaur)
Tarascolon (Tarascolon)
E Long, India.
Abelilon (Abelilon)
Majunglong (Majunglong)
Taolong (Taolong)
Kano Taurus (Kano Taurus)
Indian dragon (Indian dragon)
Ceratosaurus erectus (ceratosaurus erectus)
Majungasales (Majungasales)
Win Wang Long (Lagaron)
Scaleless dragon (scaleless dragon)
Spinosaurus
Delta dragon (delta dragon)
Alnwick Saos (alnwick Saos)
Bagaraatan (small dragon hunting)
Archaeornithoides
Heavy-legged dragon
Diplodocus (Diplodocus)
Swamp bird dragon
Yu Xialong (La Bocania)
Richard Ostesia (Richard Ostesia)
European claw dragon (European claw dragon)
Anodontosaurus
Avimimus
The wounded dragon
Yang shanlong (goat dragon)
Unenlagia (half bird)
La Hornavis, a flying bird.
Shuang Ye Long
Itemirus
Shilong (Shilong)
Cyclosaurus qinggankoulong (Cyclosaurus qinggankoulong)
Dai Nong Nong (Dai Nong Nong)
Alilong (Zhilong)
Albertosaurus (Albertosaurus)
Gorgosurus (gorgosurus)
O' brisson
Nanotyrannus (Nanotyrannus)
Style giver (style giver)
Dinosaur (dinosaur)
Shanshanlong
Fear of dragons
Tyrannosaurus rex (Tyrannosaurus rex)
Tyrannosaurus rex (Tyrannosaurus rex)
Tyrannosaurus
Tyrannosaurus rex (Tarbosaurus)
T. Luanchuan Tyrannosaurus (Tyrannosaurus Luanchuan)
Araucanorraptor (Araucanorraptor)
Boluo gouveia (Boluo gouveia)
Ostrich dragon
Byron Sarus (Byron Sarus)
Ornithopoda (ornithopoda)
Tooth-injured dragon
Narrowclaw dragon (narrow claw dragon)
Fear of birds (fear of birds)
Orcomimus-like
Birds like Garudimimus.
Gallimimus-like
Goose-like
Like an emu dragon.
Birch order (Birch order)
An ostrich-like dragon
People in China like birds.
Draco (Nomingia)
Heyuan Dragon (Heyuan Nia)
Kananahus (Kananahus)
Asian monitor lizard
Spinal stenosis
One-legged dragon
Bury the fire dragon (Citipati)
Shell Tyrannosaurus (Shell Tyrannosaurus)
Female camel dragon (Ingenia)
khan
Oviposition raptor
Alvarez dragon.
Patagonian claw dragon (Patagonian claw dragon)
Mononychus (Mononykus)
parvovirus
Shuvuuia (bird-faced dragon)
achillobator
Adalong (Adalong)
Bambi Teratosaurus
Korean dragon (Korean dragon)
Giant Raptor (Giant Raptor)
Pyrraptor
Mutant Raptor (Mutant Raptor)
Atrophic dragon (atrophic dragon)
Zhuo Meilong (Zhuo Meilong)
Bird-billed dragon (bird-billed dragon)
Erlianlong
Inner Mongolia Dragon (Inner Mongolia Gulong)
Northronicus (Northronicus)
Hidden dragon (secret dragon)
Dragon of death
Nanxiong Dragon (Nanxiong Dragon)
Segenolon
Jilong (Kamakura era)
Animal bone dragon (animal bone dragon)
Pterosaur australis
Bugenasaura (Bugenasaura)
Strange dragon (cylon dragon)
Tarancorn
Ode Romers
Paqueron (Paqueron)
Long-nosed dragon (Lofohorsaurus)
Rhabdomyolysis (rhabdomyolysis)
Mochlodon
Zalmoxes (Zalmoxes)
Slow-moving dragon (Ankylosaurus)
Bird foramen (bird foramen)
Widowed dragon
Gaspari nylon (Gasparinisaura)
Chief Dragon (Dragon Dragon)
AnaBuys dragon (Anabisetia)
Bihar dragon (Bihar dragon)
Paraodon (Paraodon)
flat
Craspedo East (Craspedo East)
Hai pu Xi Bei ma
Wide wild dragon (wide wild dragon)
mandschurosaurus amurensis
Erectile dragon (erector dragon)
Dragon (Lonely Dragon)
Former Hadro (former Hadro)
Crotalon (Crotalon)
Gilmour Dragon (gilmour Dragon)
Telmatosaurus (swamp dragon)
Dragon (three dragons)
Gadolong
Pterosaur (pterosaur)
Elombia (Elombia)
Bactrosaurus (Bactrosaurus)
Qingdao Dragon (Qingdao Dragon)
Xia Long
Parasaurolophus (Parasaurolophus)
Japanese dragon (Japanese dragon)
Heilongjiang dragon (Heilongjiang dragon)
Jack Sloan (Jack Sloan)
Blue Dragon
Olorotitan with fan crown
Bathpordia (Bathpordia)
Guanlong
Hyperion (Hyperion)
Duckbilled Dragon (Duckbilled Dragon)
Little duck-billed dragon; magby
G bellows dragon (Kerberosaurus).
Shuangmiaolong (Shuangmiaolong)
Dragon (Theseus)
Short-tailed dragon (short-tailed dragon)
dragon dance
Longlong (Longlong)
Gryposaurus (Gryposaurus)
Little Noble Dragon (Critto Dragon)
Anatotitan (Anatotitan)
Edmontosaurus (Edmontosaurus)
Shandong Dragon (Shandong Dragon)
Tanius (Tanius)
Protodinosaur (protodinosaur)
saurian
Tianzhulong
Ankylosaurus (ankylosaurus)
Black Mountain Dragon (Black Mountain Dragon)
Peishanlong
Prikonoton (Prikonoton)
Pika (pika)
Stegosaurus (stegosaurus)
Ancient Ili dragon
Mugualong
Carnivorous dragon
Abandoned robot dragon
Sauropods (sauropods)
Nodosurus (nodosurus)
Struthiosaurus (Struthiosaurus)
Niobranon
Texan
animal
Edmonton Ankylosaurus (Edmontonia)
Sylvester (Sylvester)
Panlong (Panlong)
Sauroposeidon sauroposeidon (Sauroposeidon sauroposeidon)
Tsagantegia (White Mountain Dragon)
Marius (Marius)
Shanxi Dragon (Yamashita)
Talarurus (Talarurus)
Xu Long ()
American dragon (American dragon)
Cephalopods (Cephalopods)
Tarchia (Tarchia)
Manicure Long (Saichanya)
Baotou dragon (true head dragon)
Draw a dragon (Pinacosaurus)
Clayton dragon
Short-legged dragon (short-legged dragon)
Megalodon (Megalodon)
Tula ceratosaurus (Tula ceratosaurus)
Fine-horned suborder
Before starting a business
Ceratosaurus asiaticus
Microceratosaurus (Microceratosaurus)
Slender gyro (slender gyro)
Uda ceratosaurus
White horned dragon (white horned dragon)
Kulera Topsy
Sela Topsy
Chamsron (Chamsron)
Polyonax (Polyonax)
Oolong (oolong)
Pentagonal gyro (pentagonal gyro)
Anchiceratops (ceratosaurus)
Aleurosaurus (Aleurosaurus)
Niujiaolong
Diptera (Diptera)
Triceratops (Triceratops)
Thick-nosed dragon (thick-nosed dragon)
He Shenlong (He Long)
Monoclones (Monoclonus)
Short horned dragon (short horned dragon)
Eniosron
Benzoin dragon (benzoin dragon)
Center dragon
Avaceratops (Avaceratops)
Agasomas (Agasomas)
Mandibular deformity (mandibular deformity)
Aleurosaurus (Aleurosaurus)
Bagaceratops (bagaceratops)
Ramallah Topsy (Ramallah Topsy)
Platypus (platypus)
Brevikla Topsy
Protoceratops (protoceratops)
Magno Strids (Magno Strids)
Yueqianlong
Montana ceratops (Montanoceratops)
Pachycephalosaurus (pachycephalosaurus)
Styx dragon (Styx dragon)
Microcephaly (microcephaly)
Gravity dragon (gravity dragon)
Forebrain (forebrain)
Taylor brain (Taylor brain)
Sphaerothulus (Sphaerothulus)
Stegosaurus (stegosaurus)
Posterior cranial head malformation
Ornatotherolus (Ornatotherolus)
Micropachycephalosaurus (Micropachycephalosaurus)
Goyocephala (Goyocephale)
Wan Nanlong (Wan Nanlong)
? South Indian dragon
Qinling dragon (Qinling dragon)
Hisatosaurus (Hisatosaurus)
Giant neck dragon (giant neck dragon)
Shanlong
Egyptian dragon (Egyptian dragon)
Bruhart Kaylon (Bruhart Kaylon)
Curved dragon
Curved toothed shark (curved toothed shark)
Northern Dragon (Northern Dragon)
Huabeilong
Snake dragon (snake dragon)
Gao Qiao Dragon ()
Jinuolong (Jinuolong)
Majaron (Majaron)
Pellegrini nylon (Pellegrini nylon)
Epachthosaurus
Argentinean dragon (Argentinean dragon)
Slender dragon (Lilalong)
Antarctic dragon (Antarctic dragon)
Bonita Dragon (Sura, bonita)
La Plata dragon.
Nemeron (Nemeron)
Magic dragon
Raping dragons (raping dragons)
Alamolon
Yinlong
Titan dragon
Isilon
Lin kanglong
Wind dragon; Fenglong
Gondwana Titan (Gondwana Titan)
Epithelial carcinoma of posterior urethra
Newken ken dragon.
Rocaron
Saltalon (Saltalon)
Otto cologne (Otto cologne)
Tawa Luo Long (Tawa Luo Long)
Duo mei ke long
Southern horned dragon
Apsara Weiss (Apsara Weiss)
Apartonis (Apartonis)
Fish bird (fish bird)
Limena Weiss
Yellow bird
Anisz, Pasqui (Anisz, Pasqui)
ducker
Judinonis
Chalk bird
Asian yellow bird
Paracania
Yellow bird (yellow bird)