Dinosaur

Dinosaurs were animals that lived 100 million years ago. Some dinosaurs were more like reptiles while others were more bird-like. Although many creatures are sometimes called dinosaurs, dinosaurs did not fly or live in the ocean. 

Kingdom:Animalia
Phylum:Chordata
Class:Reptilia
Superorder:Dinosauria 

What did they eat? 

Most dinosaurs lived off of plants, but some were carnivores and ate meat. The carnivores have become famous in the movies like Jurassic Park. The T-Rex and the Velociraptor are two of the scary carnivores. 

How do we know about dinosaurs? 

We know about dinosaurs from fossils that are found in the ground. From fossils, scientists are able to recreate whole skeletons of dinosaurs and determine what the dinosaurs were like. Some of these fossils and skeletons can be seen in museums. Fossils of dinosaurs have been discovered on every continent of the world. Fossils from the same type of dinosaur have been found on different continents as well.

Were they all big? 

Dinosaurs, in general, were very large. Some dinosaurs are thought to have been 40 feet tall or more. This is twice as tall as the tallest giraffe ever. There were also some smaller dinosaurs that were just a foot or so tall. There were a wide variety of dinosaurs from giant lumbering plant eaters that walked on four legs to fast dangerous meat eaters that could run on two legs. 

Why did they go extinct? 

Well, scientists aren't 100 percent sure, but many think that the dinosaurs went extinct when a giant meteorite hit the Earth. When the meteorite hit, it sent up dust and dirt into the sky covering up the sun for a really long time. This caused all the plants to die, and soon the dinosaurs died too. 

Biggest, Fastest, Tallest

There is a lot of debate on which dinosaur is the biggest, smallest, smartest, etc. We don't know for sure, but we can take a good guess using the latest information from paleontologists.

Biggest - The biggest dinosaur we currently know about is the Argentinosaurus. Paleontologists estimate it weighed up to 100 tons and measured 120 feet long.

Smallest - The Microraptor may be the smallest dinosaur ever. It was only about 16 inches long, about the size of a pigeon.

Biggest carnivore - The really big dinosaurs were all herbivores, but the biggest one that ate meat was the Spinosaurus. It weighed around 8 tons. The T-rex was one of the biggest carnivores as well.

Smartest - We don't really know for sure how smart dinosaurs were, but best guess is that they weren't very smart. However, the smartest was likely the Troodon. It is thought that the T-Rex was pretty smart for a dinosaur as well.

Dumbest - The stegosaurus was likely one of the dumbest dinosaurs. It was a giant animal with the brain the size of a ping pong ball.
Fastest - The Ornithomimus was likely a very fast dinosaur. It was a lot like an ostrich and probably ran as fast, or faster, than an ostrich at speeds of 40-50 miles per hour.

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