Top 8 Swimming & Water Dinosaurs

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If you’re a fan of dinosaurs, do you have an idea about can dinosaurs swim in the water? Do you know any popular water dinosaurs in Jurassic World? And do you know the dinosaur names?

If you don’t know, then check out these top 8 water dinosaurs in the prehistoric era!

While we may not know everything about these animals, we do know that they were some of the most feared predators during the dinosaur age. These creatures were massive, and some of them could even reach lengths of over 40 feet!

1. Can Dinosaurs Swim in the Water?

Dinosaurs had the same motivation to swim as beavers or ducks, instinctively getting them to take a dip in the water. Paleontologists say they may have swum to find food in the water, to avoid predators, to cool their bodies, to move from one store to another, or even to swim across rivers or bays, among other things.

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Like all reptiles, dinosaurs breathed air and had to do so regularly, whether they were underwater or on the water. Therefore, dinosaurs were also good at swimming in order to maintain normal breathing.

While most dinosaurs roamed primarily on land, some, such as Spinosaurus and Baryonyx, were probably amphibious. Both of them had anatomy similar to that of a crocodile. these huge creatures’ skeletons have huge skeletal spines that look like sails.

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In addition to the bones, paleontologists have found traces of dinosaurs swimming in the water. Some tracks suggest that this species swam by kicking the ground in shallow water, much like a boatman pushing a boat with a pole.

For example, in 2007, paleontologists from the University of Nantes found trace fossils (not paw prints) made by dinosaurs with their claws on the bottom of a lake, suggesting that species did swim, and the marks were their claws as they swam. Produced by scratching through sandstone.

2. What is the Biggest Water Dinosaur?

One of the biggest water dinosaurs was the Spinosaurus, which was 40 feet long. It was regarded as the largest meat-eating dinosaur in the world, which is six times longer than T-rex.

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Spinosaurus has also been the first dinosaur discovered to have ever swum, according to a 2014 research published in the academic journal Science. So, it is no wonder that Spinosaurus was the biggest water dinosaur to ever exist.

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Even though it mostly preyed on fish or catch aquatic prey, they wouldn’t pass up the chance to devour a delectable ancient mammal. Due to their desire for carnivores and aggressive tendencies, the Spinosaurus posed a threat to most reptiles. It also on the list of Top 15 Coolest Dinosaurs to Ever Lived on Earth and Top 15 Friendliest Dinosaurs Ever.


Now, you can bring home your very own version of this amazing dinosaur with the Jurassic Park Spinosaurus animatronic. This life-sized replica has moving eyes, head, and tail, and makes realistic sounds that are sure to send a chill up your spine.

More Spinosaurus facts for kids are available in Only Dinosaurs.

3. Other Aquatic Dinosaurs in the Dinosaur Age

(1) Liaoningosaurus (a type of Ankylosaurus)

In the early Cretaceous Period, a strange category appeared among the Ankylosaurs: Liaoningosaurus. Liaoningosaurus lived in China and were unique species closely related to Ankylosaurian.

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Where is the strangeness? Ankylosaurus was a terrestrial herbivorous dinosaur. But the Liaoningosaurus was an exception, they survived by catching fish in the water.

If you have no idea what Ankylosaurus is? You must remember Ankylosaurus in “Jurassic World“, the clever I.rex turned the Ankylosaurus over (like a tortoise) and bit through its unarmored belly. You may wonder if they could survive if they were swimming dinosaurs.

(2) Baryonyx

Baryonyx got its name from the large claws on the forelimbs. It is very different from other carnivorous dinosaurs. Except for the forelimbs that are not very degraded like other large theropod dinosaurs (such as T-rex), the mouth and teeth are also similar to crocodiles, and may also feed on fish like crocodiles.

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The teeth and upper and lower jaws of Baryonyx are very similar to those of crocodiles, and it is very likely that it lived near the water, or dived into shallow water, and used its terrible claws to prey on crocodiles, much like a large grizzly bear. The teeth of Baryonyx are conical, not the beef knife shape of the ordinary carnivore. They are not suitable for the role of predators, but they will eat dead dinosaurs. There is also a dinosaur whose teeth are also worthy of attention. You can click on the blog What Dinosaur Has 500 Teeth? Get to Know the Cool Nigersaurus to find out.

(3) T.rex

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Recently, a dinosaur documentary produced by Apple TV, “Prehistoric Planet“, is in great popularity. Have you seen it? If you did, you must be impressed by a T-rex family swimming in the sea.

So, Can T.rex swim? Yes! Desbite the short legs, T-Rex could swim. However, because they’re large and heavy, it’s likely that they would’ve had a hard time moving quickly in water.

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They were built for speed and power so they can easily crush their prey in their jaws. There are people who think that Tyrannosaurus Rex swam in water like penguins and sea lions.

A T-Rex is not a penguin, however. A penguin is very agile in the water while a T-Rex is clumsier. Also, a seal puts its flippers forward when swimming while those prehistoric creatures have their forearms and claws forward during swimming.

4. Some "Water Dinosaurs" are Misunderstood by Us

After looking at the water dinosaurs discovered 65 million years ago, are other “water dinosaurs” misunderstood by us? Now, we will tell you that those “water dinosaurs” are actually sea monsters that live in the sea.

(1) Plesiosaurs

If someone is asking what are the water dinosaurs with long necks? That probably mentions Plesiosaurs lived in the early Jurassic Period. But is a Plesiosaur a marine dinosaur? Like all marine reptiles, plesiosaurs evolved from different ancestors on the reptile family tree and are not technically giant lizards.

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In the Apple TV Prehistoric Planet, there is a female Plesiosaur that gave birth to a baby dinosaur in the water like sharks rather than laying eggs.

The Plesiosaurs have iconic shapes like snakes passing through the tortoiseshell: a small head, a long neck, a tortoise-like trunk, and a short tail. Although the head is small, there are many slender conical teeth in the mouth, which should not be underestimated for catching fish.

We don’t see many swim tracks in the fossil record which suggests that giant lizards probably live in water. Plesiosaur skeletons will provide us with a piece of solid evidence of it.

We don’t know for certain what happened to those creatures 65 million years ago, but we do know that the extinct marine reptiles along with the dinosaur. Many people believe that the so-called Loch Ness sea monsters were actually plesiosaurs that survived the extinction, but we have no way of knowing for sure.

(2) Mosasaurs

If you are a fan of the Jurassic Park series, you will not forget the thrilling scene of dinosaurs in the water.

In “Jurassic World”, visitors can enjoy the shocking scenes of Mosasaurs devouring an entire great white shark in the lagoon or underwater observation deck area. This marine reptile ate the T-rex at end of “Jurassic World Ⅰ”.

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The top predators in the Mesozoic ocean, Mosasaurs, were marine reptiles that lived for a relatively short period. Top predators in the Mesozoic ocean, Mosasaurs were sea dinosaurs that lived for a relatively short period. Although they are often confused for water dinosaurs, Mosasaurs are not technically classified as such.

In 2008, a group of paleontologists made an amazing discovery. They found well preserved mosasaur fossils that included soft tissue which gave scientists a new idea about what the creature’s tail may have looked like.

Mosasaurs swept away their competitors in the ocean for 5 million years. They were the most successful predators among large marine reptiles and were the overlords of the ocean 66 million years ago.

(3) Ichthyosaurs

Based on fossil evidence, Ichthyosaurs first appeared around 250 million years ago. Ichthyosaurs were large fish-like in appearance and their name comes from the Greek word that means “fish lizard”.

These ancient reptiles could grow up to 10 (or even 40) feet long and eat a wide variety of small prey.

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Those species had ruled the oceans during the Mesozoic era, just like the great white shark today. The oldest known Ichthyosaurs is “Halisaurus”, from the Early Triassic Period of China. More advanced species evolved during the Middle Triassic Period.

The dominant Ichthyosaurs were the Ophthalmosaurids, a group that had reached gigantic sizes. Growing up to 15 meters in length, these creatures had long snouts and tapered bodies, with short tails like that of a dolphin or sharks.

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Ichthyosaurs were also adept at the pursuit of predators and fearsome fighters. These species defended themselves by slashing prey with their teeth and then swallowing them whole. Ichthyosaurs’ lower jaw allows them to scrape food off the sea floor and then swallow it whole.

Do Ichthyosaurs still exist? Ichthyosaurs were a group of marine reptiles discovered that became extinct tens of millions of years before the late Cretaceous Period extinction. This event marked the end for dinosaurs and the beginning of the age of mammals.

Ichthyosaurs were among the many creatures that perished during this mass extinction.

(4) Nothosaurs

The streamlined swimmer was not a dino. Nothosaurs had webbed feet, elongated bodies, necks, and long tail. Nothosaurs (Order Nothosauria) includes the family Nothosauridae (Nothosaurus, Lariosaurus, and Ceresiosaurus) and the family Pistosauridae (Pistosaurus – more like a Plesiosaur).

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Nothosaurs were large reptilian animals that lived during the Triassic period. These marine reptiles were similar to amphibian counterparts and different from the other marine reptiles, with four flipper-like limbs which gave them more control over land and sea. They are good swimmers that prey on fish in the seas.

These creatures are not dinosaurs, but reptiles. The main difference between giant lizards and other reptiles is that they could grow much larger than others!


Now you know the previous 4 dinosaurs are real water dinosaurs, while 4 animals later are not but marine reptiles. These prehistoric creatures were wiped out from the earth forever. If you wanna know more special dinosaurs like these, the blog 10 Dinosaurs with Head Crests That are Fun to Learn About is also a good choice. Of course, it would be great if you could see their fossils up close at your local natural history museum.

In paleontology, scientists try their efforts to uncover the mysteries under these animals’ fossils discovered by science. Only Dinosaurs also hope we can relife them by our team’s crafting.

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