Fun Mosasaurus Facts For Kids | Kidadl


Fun Mosasaurus Facts For Kids

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Yes, this is the hero that drags down the Indominus rex dinosaur from the 'Jurassic Park' movie series. The genus Mosasaurus is a group of extinct aquatic animals under the order of Squamata. These marine animals are estimated to have lived during the Campanian and the Maastrichtian age of the Late Cretaceous period around 82-66 million years ago.

The skull fossil was the first-ever specimen of these marine reptiles which was discovered during the late 18th century in Maastricht. There has been an endless debate about whether these extinct reptiles were closely related to the snake or lizard family, but in 1808, Georges Cuvier, known as the father of paleontology, confirmed that these animals shared traits with the modern-day monitor lizard and snakes. These mosasaur fossils have been found around North America, Antarctica, South America, Europe, and Africa.

In addition, the Mosasaur was an apex predator with a skull made for crushing and teeth designed to tear through the flesh of prey such as fish, even sharks, and also other mosasaurs. They fed on almost anything, from sea birds to sharks, and marine reptiles to other mosasaurs as well.

 If ancient marine reptiles leave you in a sense of awe, check out the Ornithosuchus and the Clidastes.

Fun Mosasaurus Facts For Kids

What did they prey on?

Birds, fish, sharks, plesiosaurus

What did they eat?


Average litter size?


How much did they weigh?

15.43-27.55 ton (14,000-25,000 kg)

How long were they?

49.4-59 ft (15-18 m)

How tall were they?

6.5-9.8 ft (2-3 m)

What did they look like?

Primitive marine reptile

Skin Type


What were their main threats?

Natural disasters

Where were they found?

Ocean waters and open seas


North America, Western Europe, Antarctica









Scientific Name

Mosasaurus hoffmannii, M. missouriensis, M. conodon, M. lemonnieri, M. beaugei

How scary were they?


How loud were they?


How intelligent were they?


Mosasaurus Interesting Facts

Was the Mosasaurus a dinosaur?

No, the Mosasaurus was a marine reptile that is closely related to modern-day lizard species and snakes rather than dinosaurs.

How do you pronounce 'Mosasaurus'?

The word 'Mosasaurus' is pronounced as 'moe-za-sore-us'.

What type of prehistoric reptile was a Mosasaurus?

Mosaurus is a genus of squamate aquatic reptiles which is similar to aquatic crocodylomorphs, ichthyosaurus, and archaeocete whales.

In which geological period did the Mosasaurus live?

Mosasauruses are estimated to have lived during the Campanian and the Maastrichtian age of the Late Cretaceous period.

When did the Mosasaurus become extinct?

Based on the fossils, this ancient reptile went extinct around 82-66 million years ago.

Where did a Mosasaurus live?

Based on the fossil remains and the locations in which they were found, the Mosasaurus inhabited the three seaways of the Cretaceous period, namely the Atlantic Ocean, the Mediterranean Tethys (now Africa, Europe, and the Middle East), and the Western Anterior Seaway (now North America). In modern times, the various specimen types were discovered near the coasts of Canada, the USA, Turkey, Europe, the Levant, the West African coast (South Africa to Morocco), Russia, Antarctica, Argentina, and Brazil.

What was a Mosasaurus' habitat?

Fossils of the Mosasaurus were discovered in offshore habitats during the Cretaceous period. After analyzing the fossils, Mosasauruses are estimated to have lived in oceans with a depth of around 160-490 ft (48.7-149.35 m), and these waters had a variety of sea animals and fluctuating temperatures. However, the M. hoffmannii, the type species, is said to have lived near the surface of pelagic waters (open seas or oceans) based on its body shape and structure.

Who did a Mosasaurus live with?

Based on the fossil remains, it is confirmed that Mosasauruses lived among other large mosasaurs such as the T. bernardi and the P. saturator. It is also speculated that these species coexisted because they had different diet preferences with the Mosasaurus choosing soft prey like fish or sea birds and the P. saturator eating hard foods like ammonites and turtles. Although, the was able to eat hard prey because its jaws were built for a wider range of food types as compared to other mosasaur species. This niche as well as resource partitioning meant they foraged in different locations, which would mean no territorial conflict. However, they did get into competitive conflicts which are suggested by fractures on the braincase of the M. hoffmannii.

How long did a Mosasaurus live?

The lifespan of the Mosasaurus has not been analyzed.

How did they reproduce?

The exact reproduction method of the Mosasaurus has not been confirmed with the discovered evidence. However, based on the structure of the pelvis in several specimen types of Mosasaurs, it has been confirmed that they did not lay eggs and that it was viviparous, which means this marine animal gave birth to live young ones in the water, like the blue whale.

Mosasaurus Fun Facts

What did a Mosasaurus look like?

These mosasaurs had streamlined bodies with elongated skulls and a two-pronged tail.

The Mosasaurus was great at swimming and was also a killing machine. Their bodies are streamlined with flippers instead of feet and a two-lobed tail fin. Their tail was almost similar to those of sharks but inverted. These aquatic reptiles had a large skull that made up one-tenth of their body with tapering, resilient jaws, sharp teeth, and a short, blunt snout. The teeth of different Mosasaurus species had variations, but the common feature among all is that they had a prismatic surface, perfect for tearing through almost any animal. Some species have slender teeth while others show serrations, and some teeth were crenulated.

How many bones did a Mosasaurus have?

Although the exact number of bones in these mosasaurs is unknown, it is confirmed that all species of Mosasaurus have seven cervical vertebrae with variations in other vertebral bones. The fossils of M. conodon suggest that they had around nine pygal and 36 dorsal vertebrae, whereas the M. hoffmannii had around 10 pygal and 32 dorsal vertebrae, and the M. missouriensis had around 11 pygal, 33 dorsal, and 79 caudal vertebrae. The highest recorded number of vertebrae among these mosasaurs is of the M. lemmonieri, which is, 22 pygal, 40 dorsal, and 90 caudal vertebrae. In terms of a complete vertebral column, a specimen of M. conodon ranks the highest with eight pygal, 38 dorsal (including lumbar and thoracic), 68 caudal, and seven cervical vertebrae. In addition to these, several other bone fossils such as the scapula, humerus, radius, ulna, ilium, femur, and five pairs of phalanges and metacarpals have also been recovered.

How did they communicate?

Although the exact communication pattern of the Mosasaurus has not been identified based on fossil remains, they could have understood each other through visual display. To support this speculation, scientists have found that good vision which was provided excellent sight for a two-dimensional environment near the surface of the water.

How big was a Mosasaurus?

These mosasaurs were 49.4-59 ft (15-18 m) in length, still smaller than the blue whale, and with a height of around 6.5-9.8 ft (2-3 m). The Titanosaur is the largest dinosaur found, estimated to be around 118 ft (36 m) and weighing around 70-80 tons (63503-72574.8 kg).

How fast could a Mosasaurus move?

The discovered fossils suggest that these were entirely aquatic whale-like reptiles that could move efficiently and quickly through the water thanks to their streamlined body.

How much did a Mosasaurus weigh?

The Mosasaurus weighed around 15.43-27.55 tons (14,000-25,000 kg) which is around the same as a whale shark.

What were the male and female names of the species?

The male and females of this species do not have separate names.

What would you call a baby Mosasaurus?

A baby Mosasaurus would be called a juvenile.

What did they eat?

This whale-like marine animal was an active predator and often fed on sharks, bony fish, marine reptiles, cephalopods, seabirds, turtles, and other Mosasauruses.

How aggressive were they?

Since these were apex predators, and among the largest ones at that, these animals are speculated to have had high levels of aggression especially since they live among a group of several other large Mosasauruses.

Did you know...

The Mosasaurus makes an appearance towards the end of the 'Jurassic Park' movie series with its swimming skills and heroic act of taking down the Indominus rex.

Although the Mosasaurus' size is almost similar to the massive prehistoric shark, in a megalodon vs Mosasaurus kerfuffle, these mosasaurs would most likely lose because the megadalon had a wider, stronger jaw, and the Mosasaurus would not be able to wrap its jaw around its opponent's thick body.

Why is it called 'Mosasaurus'?

Although Georges Cuvier concluded that these mosasaurs were related to modern-day monitor lizards, he never gave them a scientific name. Later in 1822, Willian Daniel Conybeare named it Mosasaurus because its fossil was first found in the River Meuse.

How many teeth does a Mosasaurus have?

In each jaw, these mosasaurs have 12-16 maxillary teeth and two premaxillary teeth. The upper jaw holds 8-16 pterygoid teeth, while the lower jaw has 14-17 dentary teeth.

Here at Kidadl, we have carefully created lots of interesting family-friendly prehistoric animal facts for everyone to discover! Learn more about some other dinosaurs from our Arizonasaurus facts and Nothosaurus facts pages.

You can even occupy yourself at home by coloring in one of our free printable Mosasaurus coloring pages.

Kidadl Team
Written By
Kidadl Team

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