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Today many people know about our birds, amphibians and reptiles. But millions of years ago much larger reptiles used to roam the Earth.
What were these massive animals? They were dinosaurs!
It is estimated there were over 900+ types of dinosaurs. Many of these dinosaurs are now the ancestors of the reptiles and birds that we see in our backyards!
Even though dinosaurs have not been alive for millions of years, they are still popular.
Continue reading to learn more about 25 of the most popular dinosaur species, when they lived, and why they are now extinct.
The History Of Dinosaurs
Dinosaurs are very similar to many of today’s reptiles and birds. Like all animals, dinosaurs belong to the kingdom Animalia. This Kingdom includes humans, other mammals, birds, fish, bugs, reptiles, and many more.
They are not mammals, but they are closely related to birds and reptiles. They fall outside of the class Reptilia, but are considered to be reptiles (or at least closely related) by many scientists
In fact, dinosaurs used to be categorized in the phylum Chordata which includes reptiles.
Some early reptiles that lived in the Mesozoic Era are actually thought to be dinosaurs by many people. A good example is the well-known Mosasaurus.
They lived during the Mesozoic Era, which can be broken down into three periods:
- Triassic (225 million years ago)
- Jurassic (200 to 145 million years ago)
- Cretaceous (145 to 65 million years ago)
The end of the Triassic period was when dinosaurs first started to appear.
The Jurassic period occurred around 200 to 145 million years ago. This was when species such as the Stegosaurus and the Brontosaurus lived.
The Cretaceous period lasted from 145 to 65 million years ago. This was when the Tyrannosaurus rex and the Triceratops lived. Dinosaurs went extinct at the end of the Cretaceous period, though many scientists will argue that today’s birds are dinosaurs.
Not all dinosaurs lived throughout the entirety of the Mesozoic Era. This means some species of dinosaur existed millions of years apart!
The dinosaurs lived everywhere in the world, but their world did not look like ours.
At the beginning of the Mesozoic Era, all of the continents were together in one land mass called Pangaea. Throughout the Era, Pangaea started to break up into pieces. It continually broke and drifted apart until it formed the separate continents and land masses we know today. This is why dinosaur skeletons have been discovered all around the world.
Dinosaurs are known to have gone extinct at the end of the Mesozoic Era because fossils appear in rock layers of this Era, but not in the next Era.
Since most kinds of dinosaurs were so massive, people question why they were wiped out so quickly?
Several ideas have been debated over the last few decades.
In 1980 several scientists at the University of California at Berkeley proposed the “K-T extinction”. This proposed theory began the idea that they died of a mass extinction event.
The most common and widely accepted theory revolves around an asteroid (Chicxulub impactor) that struck the Earth around the end of the Mesozoic Era, when the dinosaurs went extinct. This asteroid is located off the coast of Mexico and is 93 miles wide and 12 miles deep.
The drastic impact and change in climate caused the mass extinction event known as the K-T extinction. During this extinction, about 60% of species on Earth went extinct. All of the dinosaurs went extinct.
| Allosaurus | Late Jurassic Period | Theropods | Saurischia | 13 |
| Ankylosaurus | Late Cretaceous Period | Cerapods | Ornithischian | 12 |
| Apatosaurus (Brontosaurus) | Late Jurassic Period | Sauropods | Saurischia | 4 |
| Archaeopteryx | Late Jurassic Period | Theropods | Saurischia | 17 |
| Brachiosaurus | Late Jurassic Period | Sauropods | Saurischia | 11 |
| Carnotaurus | Late Cretaceous Period | Theropods | Saurischia | 10 |
| Coelophysis | Late Triassic Period | Theropods | Saurischia | 24 |
| Deinonychus | Early Cretaceous Period | Theropods | Saurischia | 25 |
| Dilophosaurus | Early Jurassic Period | Theropods | Saurischia | 16 |
| Dimorphodon | Early Jurassic Period | Family Dimorphodontidae | Order Pterosauria | 14 |
| Diplodocus | Late Jurassic Period | Sauropods | Saurischia | 18 |
| Europasaurus | Late Jurassic Period | Sauropods | Saurischia | 20 |
| Gallimimus | Late Cretaceous Period | Theropods | Saurischia | 19 |
| Hadrosaurus | Late Cretaceous Period | Cerapods | Ornithischian | 22 |
| Iguanodon | Early Cretaceous Period | Cerapods | Ornithischian | 9 |
| Mosasaurus | Late Cretaceous Period | Family Mosasauridae | Order Squamata | 8 |
| Parasaurolophus | Late Cretaceous Period | Cerapods | Ornithischian | 21 |
| Plesiosaurus | Early Jurassic Period | Family Plesiosauridae | Order Plesiosauria | 15 |
| Pterodactyl | Late Jurassic Period | Family Ptilodactylidae | Order Pterosauria | 5 |
| Spinosaurus | Late Cretaceous Period | Theropods | Saurischia | 7 |
| Stegosaurus | Late Jurassic Period | Family Stegosauridae | Ornithischian | 2 |
| Triceratops | Late Cretaceous Period | Ceratopsid | Ornithischian | 3 |
| Troodon | Late Cretaceous Period | Theropods | Saurischia | 23 |
| Tyrannosaurus rex | Late Cretaceous Period | Theropods | Saurischia | 1 |
| Velociraptor | Late Cretaceous Period | Theropods | Saurischia | 6 |
*There are four major orders of dinosaurs:
- Theropods are carnivorous dinosaurs. They typically walk on two legs and can be nearly any size. They are classified under Saurischia.
- Cerapods contain the species that were herbivorous and did not have long necks. This includes the Ceratopsids. They are classified under the clade Ornithischia.
- A family of Cerapod dinosaurs that includes Triceratops, Centrosaurus, and Styracosaurus. They are known for the horns on their faces and frills behind their heads.
- Thyreophorans are known as armored dinosaurs and include the Ankylosaurus and Stegosaurus. They are known for having bony body armor lined in rows on their bodies.
**There are three major types of species:
- Saurischian dinosaurs are “reptile-hipped” species and are classified by their hip structure. They are one of two major divisions, the other one being Ornithischians.
- Ornithischia is the major group of dinosaurs that directly translates to “bird-hipped”, and they are classified due to their hip anatomy.
- Pterosaur translates from Greek into “wing lizard”. They are known as flying reptiles, and are the earliest known vertebrates to fly.
Types of Dinosaurs
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25. Deinonychus
The Deinonychus was first discovered in southern Montana in 1964 when over one thousand bones were recovered. It roamed what is now the western interior of North America and central Mongolia in the early Cretaceous period.
This dinosaur is known for having sharp front claws and feathered front legs. It would use its “arms” in a flapping motion to stabilize itself, which may help link dinosaurs to today’s bird species.
It is a theropod, which is a type of dinosaur that is known for having three toes and being carnivorous.
The Deinonychus was estimated to be about 11 feet long and about 160 pounds. Though not very large, fossils suggest that it hunted bigger dinosaurs such as the Tenontosaurus.
24. Coelophysis
The Coelophysis is a saurischia theropod from the late Triassic period. It is one of the earliest known dinosaurs. Saurischian is an order of dinosaur that includes “lizard-hipped” dinosaurs.
This theropod relied on its slender body, speed, and agility to catch its prey. As a theropod, the Coelophysis was a carnivore. Its diet often consisted of smaller reptiles and insects.
The Coelophysis was about 6.6 feet in length and weighed about 50 pounds.
23. Troodon
The Troodon is another saurischia theropod from the late Cretaceous period.
It was a small, bird-like dinosaur that had three clawed toes. The egg clutches of this dinosaur links it heavily to birds. They share many similarities with birds through their hard-shelled eggs, parental care, and female reproductive systems.
The Troodon was an active dinosaur with a large brain and eyes. Its diet likely consisted of smaller birds, mammals, and reptiles.
It grew to about 8 feet in length and weighed about 110 pounds.
22. Hadrosaurus
The Hadrosaurus is known for being the first dinosaur discovered in North America. William Parker Foulke discovered the bones of this dinosaur in Haddonfield, New Jersey in 1858. Its historic importance is what has led it to become the state fossil of New Jersey.
The Hadrosaurus is a cerapod.
A cerapod is a herbivorous dinosaur that has thick enamel on the inside of their lower teeth. This dinosaur typically ate fruits, leaves, and other plants.
It is estimated that the Hadrosaurus was about 25 feet in length and weighed 5,000 to 9,000 pounds.
21. Parasaurolophus
The Parasaurolophus was a cerapod of the Late Cretaceous period. Parasaurolophus means “near crested lizard”. This dinosaur is well-known for its large head crest, like many modern types of chameleons.
It was first discovered in Alberta, Canada and is thought to have roamed North America and some parts of Asia. As a cerapod, Parasaurolophus often ate plants that included leaves, twigs, and pine needles.
The Parasaurolophus was about 36 feet long and weighed approximately 7000 to 8000 pounds.
20. Europasaurus
The Europasaurus is a long-necked dinosaur that was recently-discovered. The first remains were found in 1998 in Oker, Germany by a private collector called Holger Lüdtke.
Since 1998, thousands of Europasaurus bones have been recovered.
The Europasaurus is a sauropod that could have been found in the Late Jurassic Period.
Sauropod is a group of species that includes large dinosaurs that had very long necks, small heads, and four thick legs. All sauropods are part of the order Saurischian.
This dinosaur was predicted to have ranged from 5.5 feet in length as juveniles to 20 feet in length as adults, weighing around 1,100 pounds. This made it smaller than most sauropods.
19. Gallimimus
The Gallimimus is a theropod that was first discovered during some Palaeontological Expeditions in Mongolia in the late 1960s. It belongs to the order Saurischian and lived during the late Cretaceous period.
Several more skeletal remains have since been discovered in the Gobi Desert of Mongolia.
This dinosaur stood on two legs with small, wing-like arms. Its skeletal structure, although larger, looked like those of modern-day chickens. It was one of the first dinosaurs that had feathers, much like today’s birds.
The Gallimimus stood about six feet tall, was 20 feet long and it weighed about 1,000 pounds.
18. Diplodocus
The Diplodocus was a large sauropod from the late Jurassic period. It was first discovered in 1877 in Colorado by Benjamin Mudge and Samuel Wendell. Another skeletal piece was discovered in the Como Bluffs of Wyoming in 1897 by Barnum Brown and Henry Fairfield Osborn.
Several more species of Diplodocus have since been found in the midwestern United States. Many can be found in museums around the world.
The Diplodocus was a massive dinosaur, it stood at about 85 feet long. It weighed a large 12 tons, or 24,000 pounds!
17. Archaeopteryx
Archaeopteryx is a dinosaur known as the “first bird”.
A single feather from this species was discovered in 1860 by Hermnann von Meyer in Germany, followed by a skeleton in 1861. Several perfectly preserved fossils of the feathers have since been found.
Though not much is known about it’s specific diet, as a theropod it was carnivorous and possibly ate small reptiles, mammals, and insects.
The Archaeopteryx was a small theropod dinosaur that lived in the late Jurassic period. The largest species did not reach two feet long.
16. Dilophosaurus
The dilophosaurus is a theropod known for the two crests that sit on top of its head. In fact, its name means “two-crested lizard.” It lived in North America during the early Jurassic period and the first skeletons were discovered in northern Arizona in 1940.
Dilophosaurus were the largest known dinosaurs to have lived during the early Jurassic period.
Though large, it had a slender build. Its sleek body and powerful legs suggest that it hunted larger herbivore dinosaurs.
The dilophosaurus was about 23 feet in length and weighed about 900 pounds.
15. Plesiosaurus
The Plesiosaurus was not actually a dinosaur at all! It is often confused as an aquatic dinosaur.
Dinosaurs roamed the earth in the early Jurassic period, but these aquatic reptiles ruled the water. They were predators and fed on fish and other aquatic reptiles.
Since they are not officially dinosaurs, they are not classified under the order Saurischian or Ornithischia.
The first complete skeleton was described in 1823 by early paleontologist Mary Anning.
Plesiosaurus are known for their long neck and turtle-like bodies. While it did not have a shell, it had a wide body and flipper-like arms. They could grow upto 49 feet and generally weighed about 1,100 pounds.
14. Dimorphodon
The Dimorphodon was a pterosaur (a type of flying dinosaur) that lived during the early Jurassic period.
Unlike most dinosaurs on this list, the Dimorphodon is not in the Saurischian or Ornithischia orders. Rather it is in the order Pterosauria, a group specially from pterosaurs (i.e. flying dinosaurs).
This dinosaur was first discovered in 1828 by fossil collector Mary Anning, in England.
Some tooth scratches on the fossils of this dinosaur have indicated that it ate insects and other small land invertebrates.
The Dimorphodon had a wingspan of about four and a half feet and weighed about 4 pounds. Its body is shorter than its wingspan at three feet.
13. Allosaurus
The Allosaurus is one of the most well-known theropod dinosaurs of the late Jurassic period. It had a large body, large back legs, a large skull and two noticeable ridges over its eyes.
The first fossil of this dinosaur was found in Colorado in 1869.
Further fossils of the Allosaurus have been uncovered in the midwestern United States.
The Allosaurus is a large carnivore that averaged about 33 feet in length and 16.5 feet tall. It weighed about two tons. Like many large carnivorous dinosaurs it preyed upon larger herbivorous dinosaurs.
12. Ankylosaurus
Ankylosaurus is a cerapod from the late Cretaceous period. These herbivores likely ate low-lying plants.
The Ankylosaurus is known for its unique appearance.
This dinosaur is low to the ground and has several rows of spikes on its back. It also has a defensive tail with a boulder-like feature at the end of it.
The first description of the Ankylosaurus was in 1908 by Barnum Brown. Brown led the expedition in Montana, where collector Peter Kaisen discovered the first known specimen.
Ankylosaurus are estimated to have stood between 20 and 26 feet long and weighed around 18,000 pounds.
11. Brachiosaurus
The Brachiosaurus is one of the biggest and most well-known long-necked dinosaurs.
This sauropod species lived in North America during the late Jurassic period.
Like many types of sauropods, the Brachiosaurus was initially thought to have lived in the water to support its weight. However within the past century paleontologists began to question this. It is now widely accepted that the Brachiosaurus was a terrestrial species.
The first specimen discovered was part of a poorly-preserved skull found in Colorado.
Brachiosaurus were estimated to be between 60 to 70 feet long and weighed between 60,000 and 120,000 pounds! Due to its long neck and herbivorous diet, this dinosaur likely ate from tall trees.
10. Carnotaurus
The Carnotaurus was a large two-legged type of dinosaur with small arms and two horns above its eyes.
It is one of the best studied dinosaurs of the late Cretaceous period.
What makes this dinosaur unique is that this specimen was discovered as a whole skeleton! Most current specimens of ancient dinosaur skeletons are partial. This skeleton was discovered in 1984 in Argentina by Argentinian paleontologist José Bonaparte.
The Carnotaurus had a flexible jaw, similar to some species of snakes. This allowed it to quickly eat small mammals.
This dinosaur was about 25 to 30 feet in length and weighed about 3,000 pounds.
9. Iguanodon
The Iguanodon was one of the first dinosaurs to be discovered. It was a cerapod that lived in the early Cretaceous period.
The teeth of an Iguanodon were the first parts to be discovered in 1822. However at first these teeth were confused as belonging to a rhinoceros. They were later confirmed to have belonged to a new species of dinosaur, the Iguanodon.
Iguanodons walked on all fours, with their back legs larger than their front. It was a herbivore and is also known for its beak-like mouth and teeth.
The Iguanodon was named after both the Iguana and the Latin root “odon,” meaning teeth.
It likely stood nine feet tall and weighed between 8,000 and 11,000 pounds.
8. Mosasaurus
The Mosasaurus is another animal often confused for being a species.
Although it lived with dinosaurs, it was actually more closely related to snakes and monitor lizards. It is therefore classified in the order Squamata and is not a dinosaur.
Its skull was first discovered in the Netherlands in 1764. It was initially identified as a whale and then as a crocodile until 1808. In 1808 the skull was determined to have belonged to an extinct animal.
The Mosasaurus had a large head and a whale-like body with large front flippers, smaller back flippers, and a tail. They were large, slow moving animals and often preyed upon birds, turtles, and sharks.
It was one of the largest marine reptiles to have ever lived and was estimated to have been about 50 feet long and weighed 30,000 pounds. It was much bigger than the well-known prehistoric Megalodon shark.
7. Spinosaurus
The Spinosaurus was a semi-aquatic dinosaur, similar to many of today’s crocodiles. They walked on land and spent time in the water. It is likely that it ate large terrestrial animals as well as fish.
Several Spinosaurus bones were first discovered by Ernst Stromer in 1912 in Egypt.
Unfortunately, these bones were destroyed in the Munich bombing in April of 1944 during World War II. Some smaller samples were recently uncovered and have contributed to today’s knowledge of this dinosaur.
The Spinosaurus is the largest known land dinosaur to have lived. It is even larger than other theropods on this list such as Tyrannosaurus rex and Carnotaurus.
It ranged from 40 to 60 feet in length and weighed about 46,000 pounds.
6. Velociraptor
The Velociraptor was a small, but fast carnivore from the late Cretaceous period. This theropod often ate small animals such as amphibians, insects, and small mammals.
They are two-legged dinosaurs with small heads and sharp teeth that stood only 1.5 feet tall. However, they reached almost seven feet long and weighed about 30 pounds.
The Velocirpator was first discovered during an expedition by the American Museum of Natural History in the Mongolian Gobi Desert in 1923. A second Velociraptor species was discovered near the same area in 2008.
5. Pterodactyl
The Pterodactyl is one of the most well-known flying pterosaurs of the late Jurassic period.
It was the first pterosaur to be named and was described in 1784 by Italian scientist Cosimo Alessandro Collini. Cosimo’s description was based on a fossil of the Pterodactyl discovered in Bavaria, Germany.
The Pterodactyl is known for its head crest and three-and-a-half-foot wingspan.
The long, narrow skull and many teeth of the Pterodactyl suggests that it was a carnivore that ate small animals.
4. Apatosaurus
Some people may remember the Apatosaurus as the Brontosaurus. The Brontosaurus is in fact a subset of Apatosaurus.
The Apatosaurus is one of the most well-known sauropod dinosaurs. It lived in North America during the late Jurassic period.
They have the famous long necks that all sauropods share, however they are shorter and stockier than most species.
The term Apatosaurus means “deceptive lizard”. It is named after its chevron bones, which are very different from those of related dinosaurs. The Apatosaurus was an herbivore and likely ate a variety of trees and shrubs.
Apatosaurus grew to about 69 to 75 feet long and weighed an impressive 72,000 to 160,000 pounds.
3. Triceratops
The Triceratops is a well-known dinosaur that is a type of ceratopsid. Ceratopsids are four-legged herbivores known for their horns and a frill on the back of their heads.
Triceratops are known for their nasal horn, two horns above their eyes, beak, and frill behind their head. One possible function of these horns was combat with predators such as the Tyrannosaurus rex.
The first specimen of Triceratops discovered was a pair of horns found near Denver, Colorado. They are one of the most common dinosaur fossils found in western North America.
Triceratops reached about 26 to 30 feet in length and weighed about 13,000 to 26,000 pounds. Its skull alone was about eight feet long!
2. Stegosaurus
Stegosaurus is a four-legged thyreophoran dinosaur from the late Jurassic period.
Thyreophorans are a type of dinosaurs that have “armor” in the form of extra spikes. This group includes dinosaur species as the Stegosaurus and the Ankylosaurus.
The Stegosaurus had a large body and small head, but its most notable feature was the two rows of large spikes that lined its back.
Specimens of the Stegosaurus have been found in the United States and in Portugal. The first fossil discovered was uncovered in Morrison, Colorado in 1877.
Stegosaurus was a herbivore that grew to about 21 feet long and weighed between 11,000 and 15,000 pounds.
1. Tyrannosaurus rex
The Tyrannosaurus rex is perhaps the most recognized dinosaur today. It is famous for its small front legs, large head, and large bipedal back legs.
It is the most commonly found theropod dinosaur in North America from the late Cretaceous period. Tyrannosaurus rex teeth were first discovered in 1874 near Golden, Colorado.
A second skeleton was discovered in Hell Creek Formation, Montana in 1905.
It is widely accepted that the Tyrannosaurus rex was an apex predator, given its large size and carnivorous behavior. It likely preyed upon large herbivore dinosaurs such as hadrosaurus, ankylosaurus, and various sauropods.
The Tyrannosaurus rex could reach 40 feet long, 13 feet tall at the hips and weighed about 18,000 to 30,000 pounds.
Summary
The dinosaurs lived for tens of millions of years, many of them throughout the Jurassic and Cretaceous Eras.
There are only 25 dinosaur species on this list, but over 900 different types of dinosaurs have been discovered.
Some dinosaur were large carnivores, while others were smaller herbivores.
Dinosaurs can teach us a lot about today’s birds, reptiles and amphibians. Many of these dinosaurs are ancestors to the birds, reptiles and lizards that we see in our states!
What is your favorite kind of dinosaur? Let us know in the comments below.