Dinosaurs have roamed the earth millions of years before man ever existed. They are a mystery to us. When paleontologists first found dinosaurs they thought they were just animals that just happened to live on the planet and then died out really quickly. When they were putting the bones together, they would put together different bones that belonged to different dinosaurs. Then they looked at the bones and found out that the dinosaurs had lived 75 times longer then humans have existed.
Then Paleontologists started to pay more attention to these creatures. They soon learned that the dinosaurs were very sophisticated animals, they were very smart, and they were reptiles. When they found the bones and studied them they found out that the dinosaurs didn’t have any interaction with mankind.
Since the first dinosaur bones and their eggs were discovered; we have learned so much about dinosaurs. But there are so many mysteries out on our planet waiting to be uncovered, Maybe a new specie of a dinosaur will be discovered, or the first flying dinosaur, who knows? But whatever paleontologists haven’t found, will soon be found, bringing us closer to finding out more about dinosaurs.
There were a lot of different kinds of dinosaurs. Most of the dinosaurs were herbivores, some were carnivores, and very few were omnivores. The herbivores were peaceful dinosaurs and only ate plants. The carnivores were vicious and were eating other dinosaurs so the the carnivores only ate meat. The omnivores ate mainly meat but when there was no meat around they could eat plants.
The three main groups of dinosaurs are: Ceratopsians, Theropoda, and Saurapods. The Ceratopsians were all of the horned dinosaurs. The king of the Ceratopsians was the Triceratops. The Theropoda was a group for all of the meat eating dinosaurs. The T-Rex was the king of the Theropoda group. The Saurapods was a group of dinosaurs for long necked dinosaurs. The king of the long necked dinosaurs was the Ultrasauros. A type of Sauropod was a Brachiosaurus. The biggest dinosaur was a Sauropod. The 3 largest Sauropod were the Brachiosaurus, Ultrasauros, and Sauroposeidon.
The dinosaurs lived in the Mesozoic era where the 3 dinosaur periods look place in. The periods are the Triassic period, the Jurassic period, and the Cretaceous period. The dinosaur species started to exist in the Triassic period which happened 248 million years – 206 million years ago. The Jurassic period happened 206 million years ago – 144 million years ago. The last period was the Cretaceous period which happened 144 million years ago – 65 million years ago. Dinosaurs have roamed the earth for about 183 million years.
In the Triassic period Dinosaurs and mammals started to roam the planet. During the Jurassic period birds started to exist. Dinosaurs that lived in the Triassic period were the Coelophysis and the Anchisaurus. Dinosaurs that lived in the Jurassic period were the Brachiosaurus, the Allosaurus, and the Oritholestes. Dinosaurs that lived in the Cretaceous period were the most common dinosaurs do us. They were the Tyrannosaurus Rex or the T-Rex, the Triceratops, and the Iguanodon.
At the end of the Cretaceous period all of the dinosaurs became extinct. Some families of birds, marsupial mammals, over half of the plankton groups, many families of bony fishes, bivalves, snails, sponges, and sea urchins had also become extinct. There were many theories why the dinosaurs died out; but the main theory is that an asteroid had hit the Earth. The impact caused the Earth’s climate to become colder. The dinosaurs would soon die out because they couldn’t live in a cold climate. When the asteroid hit the earth some gasses were released into the air and blocked the sun, causing the temperature to drop. Plants that herbivores ate weren’t getting enough sunlight, so the herbivores were the first to die. The carnivores that ate the herbivores would have had to turn on each other to get their food.
They soon would die out, which left a lot of food for smaller animals like mice and insects that dinosaurs didn’t eat a lot of. The cockroach was able to survive because it was sort of like an omnivore. The cockroach would eat anything so they could have survived the asteroid attack. Evidence that supports the death of dinosaurs was that there were curators found around the earth like on the Yukatan Peninsula which paleontologist think proves that dinosaurs had died from asteroids. There were other theories of what killed the dinosaurs. During the Cretaceous period there were extreme volcanic eruptions and acid rain that could have changed the Earth’s climate enough to trigger a mass extinction. The smoke that came from the volcano could have blocked the sun allowing the climate to drop; and the lava that came from the volcano would have destroyed all of the vegetation that the herbivores ate. The lava would also kill the eggs that were just laid, so the population could’t grow. The earth’s orbit also changed, that also could have also caused the drop in the climate. During that time, large amounts of methane were changing the earthвЂ™s atmosphere which caused a greenhouse effect. All of these things could have caused the dinosaur’s extinction.