These dinosaurs lived in water: An overview

Dinosaurs that lived in water are also called marine dinosaurs. There were many different species. Most of them can be divided into three genera: Sauropterygia, Ichthyopterygia, and Mosasaurs.

Plesiosaurs are also known as “elasmosaurs” and belong to the Sauropterygia family, which lived during the Cretaceous and Jurassic periods. They had a gigantic body with a large volume and a very long neck, which made it easier for them to catch their prey. As carnivores, their diet consisted mainly of fish and mollusks.

• Facts: It was a carnivore, lived during the Cretaceous and Jurassic periods, had a body length of up to 15 meters, and was found mainly in Asia and North America.
• This giant of the sea had a very voluminous body and a long, slender neck. Its tail, fin-like legs, and small head helped it move through the water.
• For a long time, it was believed that the plesiosaur belonged to the reptile family. However, research has shown that the dinosaur’s body was not capable of leaving the water to lay eggs on land. The theory therefore followed that the dinosaur gave birth to live offspring.
• At 15 meters, the plesiosaur was one of the largest dinosaurs in the sea. However, the giant was still able to move quickly through the water thanks to the wing-like movements of its fins. This is also known as marine “flight.”

The ichthyosaur

• Facts: Ichthyosaurs were carnivores, lived from the Lower Triassic to the Upper Cretaceous period, and reached a body length of up to 18 meters. Fossils have been found in the seas of India, Europe, the Caribbean, and North America.
• The dinosaur had a fish-like body, a lizard-like head, and fins like those of whales and dolphins.
• Its huge eyes enabled it to see objects from a great distance and under difficult sea conditions. This allowed it to hunt at night when most of its prey was asleep.
• The ichthyosaur breathed air, which means that, like dolphins, it had to come up for air to breathe.
• It was a fast, enduring swimmer and deep diver, which enabled it to hunt its prey over long distances.
• Fossils of ichthyosaurs have been found with offspring inside them. This suggests that they also gave birth to live offspring.

Liopleurodon

Liopleurodon is a well-known marine dinosaur of the Sauropterygia. It was characterized above all by its large teeth, which made it a dangerous predator.

• Facts: It was a carnivore, lived from the Lower Triassic to the Upper Cretaceous period, could grow up to 12 meters long, and was found in Europe (England, France, Germany).
• The Liopleurodon reached an average length of 12 meters, with a skull alone measuring 2.2 to 3 meters.
• Liopleurodon was a visual predator. Its brain accounted for less than 1 percent of its body mass and therefore had to process information very quickly. This type of brain is also found in today’s great white shark.
• Its powerful and long front and rear fins indicate that it was a strong swimmer.
• Liopleurodon had a strong jaw with powerful teeth. This suggests that its diet consisted of larger prey rather than fish.

Hainosaurus

Hainosaurus belongs to the genus of mosasaurs from the Late Cretaceous period.

• Facts: It was a carnivore, lived in the Late Cretaceous period, reached a body length of 12-17 meters, and was found in Europe, Canada, and Antarctica.
• Its 1.5-meter-long skull was pointed and reinforced. Researchers believe that it was used to incapacitate or kill rivals or prey by ramming them.
• With a length of up to 17 meters, the Hainosaurus is considered one of the largest mosasaurs.
• The marine dinosaur probably hunted other large marine animals such as turtles, smaller mosasaurs, and, when fully grown, possibly also large fish and sharks.