There are over 700 dinosaur genera known, with over 1000 species.
The answer depends on how you define “types.”
There are many ways Paleontologists put dinosaurs into different categories, and we’re going to explain them using a Tyrannosaurus Rex as an example to make it less complicated.
First off, the Tyrannosaurus Rex is considered an Animal. Of course, you already know that, but we have to start somewhere.
Every animal belongs to a specific class.
The different classes are Mammals, Reptiles, Amphibians, Birds, Fish, and Insects.
All dinosaurs are part of the reptile class, which means the Tyrannosaurus Rex is also a reptile.
Now, what makes a dinosaur different from other types of reptiles?
Now, what makes a dinosaur different from other types of reptiles?
Animals are classified as a dinosaur if they match five different points. Such are:
1) They must have placed their legs directly underneath their body (like birds, not like lizards).
2) They live on land.
3) They’re Vertebrates, meaning they have a backbone.
4) Their skull has two holes behind their eyes.
5) They lived between 245 and 65 million years ago
Tyrannosaurus Rex, a reptile that lived 68–66 million years ago, had a backbone, lived on land, and had a skull with two holes behind his eyes, meets these requirements, making it a Dinosaur.
Now that we know what kinds of animals dinosaurs are let’s look at different types of Dinosaurs.
There are two main divisions (orders) of dinosaurs based on their hips.
Ornithischia, which means “bird-hipped.”
Saurischia, which means “lizard-hipped.”
Are you still with me?
The order “Saurischia” includes all Theropoda, groups of bipedal (=walking on two legs, like birds) dinosaurs; most were carnivorous (=meat eating animals).
Tyrannosaurus Rex and Velociraptor belong to this group.
And the “Sauropods.” That’s what you call dinosaurs with long necks. They walk on four legs and are herbivores (eat only plants).
Dinosaurs like Brontosaurus or Brachiosaurus belong to this group.
The order “Ornithischia” includes Marginocephalia, Ornithopoda, Thyreophora.
“Marginocephalia” are dinosaurs with bony projections on their skulls. One great example is the triceratops, who had a large bony frill behind his skull.
“Ornithopoda” are dinosaurs that have bird-like feet. They walked on two legs, and most of them were plant-eaters. They also had a beak. These dinosaurs are not that famous, but you may know Iguanodon and Parasaurolophus from movies or books.
The “Thyreophora” group is also known as armored dinosaurs. They had plates upon their body. Two examples are the Stegosaurus and Ankylosaurus.
That was complicated, but let's get back to our Tyrannosaurus Rex example.
Tyrannosaurus Rex was:
1) An animal.
2) A Reptile (Class).
3) A Dinosaur (group).
4) Part of the Saurischia order (group).
5) A Theropoda (a group of dinosaurs that walk on two legs, eat meat, have hollow bones and three-toed limbs).
Now comes the “family.”
6) Tyrannosaurus Rex is part of the “Tyrannosauridae” family.
I hope you’re still with me!
7) Then there’s the genus “Tyrannosaurus.”
A genus often consists of several species, but most dinosaur genera (plural of genus), including the Tyrannosaurus, have only one species.
Just as an example for a genus with several species:
A wolf is part of the Canis, a genus that includes several other species like the gray wolf, the Ethiopian wolf, the African wolf, etc.
But back to our T-Rex example!
8) And finally, we have the species, which is the Tyrannosaurus Rex.
Almost all categories but the “Species” are a group of animals.
Species describe a primary type of dinosaur/animal.
Pew that was complicated.
But we made it! And now you know the different types of dinosaurs.
Some of the most famous dinosaur types are:
Tyrannosaurus Rex lived 66 – 68 million years ago in what’s now North America. It’s a theropod (meat-eating dinosaurs that walk on two legs) from the Saurischia group.
Brontosaur lived 156 – 146 million years ago and belonged to the sauropods, a group of dinosaurs with a long neck part of the Saurischia group.
Velociraptor became famous due to its presence in several dinosaur movies. It lived 75 to 71 million years ago in what’s now China and was, just like the T Rex, a theropod (which belongs to the Saurischia).
Some of the most famous Ornithischia dinosaur types are:
Triceratops – roamed the earth 68–66 million years ago in what’s now North America. It was a herbivore from the Ceratopsia order.
Stegosaur – lived 155–145 million years ago. Fossils come from America and Portugal. It was a herbivore as well.
There are some types of prehistoric reptiles that aren't dinosaurs at all:
Plesiosaurs are an order of marine reptiles that includes several dinosaur-like animals, like the plesiosaurus. They don’t fit the dinosaur criteria, though, because their legs don’t come out directly under their body, and they’re fully aquatic, which means they live in water.
Pterosaur is an order of flying reptiles. But, unfortunately, they don’t fit the dinosaur criteria either. Even though modern birds are considered dinosaurs, they’re not related to Pterosaur but more closely to some theropods.
