Mosasaurus
Mosasaurus hoffmannii • "Meuse River Lizard"
Mosasaurus was a large marine reptile in the mosasaur group, related to modern lizards and snakes rather than dinosaurs. It lived in Late Cretaceous seas and had paddle-like limbs and a powerful tail for swimming.
- Length
- ≈17 m
- Weight
- ≈14.0 t
- Diet
- Carnivore
- Danger
- ★★★★★
Overview
The oceanic leviathan of the Late Cretaceous. Mosasaurus was a gigantic marine squamate closely related to modern monitor lizards and snakes, ruling the prehistoric Western Interior Seaway.
“The first Mosasaurus skull discovered in 1780 in a limestone quarry near Maastricht was considered so valuable that French revolutionary forces bombarded the city to capture the specimen.”
Key facts
Strengths
- Absolute marine apex dominance
- Crushing jaw bite force (13,500 PSI) with secondary throat teeth
- Explosive vertical ambush acceleration from the oceanic abyss
Weaknesses
- Completely helpless on dry land
- Air-breathing reptile that must periodically surface
Natural weapons
- Dual row of pterygoid teeth in the upper palate to prevent prey escape
- Powerful crescent tail fin generating explosive ambush thrust
- Massive crushing jaws able to swallow plesiosaurs and giant turtles whole
Movies vs. science
Myth: Jurassic World portrayed it as an oversized 25-meter blue whale titan.
Reality: Real Mosasaurus reached a realistic 17 meters and 14 tonnes—still the supreme marine predator of its era.
Size & simulator stats
Length estimates for the largest species range from roughly 11–12 m to 17–18 m. Most remains are skulls, so total length is inferred and debated.
- Length
- 17 m
- Height
- 3.5 m
- Weight
- 14.0 t
Illustrative simulator values (not measured biology)
See how Mosasaurus measures up in the sourced size comparison chart.
Habitat
Warm, shallow epicontinental seas, coastal estuaries, and open oceanic waters.
Marine environments, with fossils found in Europe, North America, and elsewhere.
Diet
Hunted giant sea turtles (Archelon), plesiosaurs, ammonites, sharks, and birds.
Carnivore. Fossils and stomach contents show mosasaurs ate fish, squid, sharks, and sometimes other marine reptiles; diets varied by species.
Fossils & discovery
First described from Netherlands, North America, Europe in 1764 (Maastricht Formation (Netherlands)).The first Mosasaurus skull discovered in 1780 in a limestone quarry near Maastricht was considered so valuable that French revolutionary forces bombarded the city to capture the specimen.
Research sources
Sources checked on by the Dinosaurs Names Editorial Team. Editorial policy
Gallery
Related dinosaurs
Battle Arena
Can anything beat Mosasaurus?
Send Mosasaurus into an illustrative matchup against any other species and compare attack, defense, and bite force.
Fight as Mosasaurus