Sea holds secrets. Throughout the history of the earth, oceans were home to many creatures including the very first forms of life. Sailors created sea monster stories from their misunderstood experiences in the ocean.

Island Sea Ocean Sky Cloud Water  - Barroa_Artworks / Pixabay
Barroa_Artworks / Pixabay

But a long time ago in the age of reptiles, there were real creatures who can be considered sea monsters. Here are the ten biggest aquatic monsters around the Jurassic age.

Crocodile-looking monster pliosaurs

  • Order: Plesiosauria
  • Class: Reptilia
  • Kingdom: Animalia
  • Clade: Neoplesiosauria

A pliosaur may look like a historical crocodile to you. But they are not direct relatives. Pliousurus is one member of the pliosaurs family which include many aquatic monsters in the Jurassic age.

Pliosaurus were adopted to hunt other marine reptiles. So, they had relatively short but massive necks and broad flippers. They roam the European and South American seas in the late Jurassic period (150 to 145 million years ago).

A large pliosaur was 40ft long and had 30 tons of weight. They had a strong bite that beat Tyrannosaurus rex bite power by 4 times. That must have helped these aquatic monsters in the Jurassic age to hunt their reptile prey.

Powerful biter Kronosaurus

  • Family: Pliosauridae
  • Kingdom: Animalia

Kronosaurus also belongs to the Pliosauridae family. It is named after the king of Greek titans Cronus. They have been found all over the world, especially in Australia. Kronosaurus is predicted to live in Aptian to Albian of Cretaceous.

Identical massive jaws, large head, and short neck Kronosaurus weighed 12 tons and longer than 34ft. It had a tich squarish trunk.

Their teeth were not sharp but do not misunderstand them. The Kronosaurus bite is extremely powerful not to mention the super high speeds it can reach when it is following the prey.

Head snapper Nothosaurus

  • Order: Nothosauroidea
  • Phylum: Chordata

Nothosaurus means false lizard. The name came from the experts who still can’t determine if they laid eggs or gave birth to their babies. They are found in Europe, North America, Africa, and China. They live in Anisian to Norian of the Triassic period (230 million years ago).

A Nothosaurus was 15ft long and had needle-sharp teeth. One interesting thing about them is they had a habit of catching fish very similar to what crocodile does. They snap their head sideways and catch a passing fish.

These aquatic monsters share a lot of commonalities with modern sea lions, Nothosaurus live and hunt on the sea but came out of shore to rest.

Snake longer Styxoaurus

  • Family: Ceratopsidae
  • Subfamily: Centrosaurinae
  • Kingdom: Animalia

Styxoaurus can be mistaken as sea snakes if you only see the neck part. They had that many long necks. Styxoarus is 45ft in length. 35 ft of that (78%) is their neck.

They lived 85 to 70 million years ago in Santonian to Campanian of the Cretaceous. Another special characteristic of them is razor-shaped teeth that helped them to cash their prey. But they didn’t need to use them to chew because an interesting digesting technique. Their bellies had 200 small stones called gastroliths for that. Alternatively, they could have used them to sink to the bottom of the ocean in search of particular fish.

Hardneck Albertonectes

  • Family: Elasmosauridae

Albertonectes is also a member of the Pliosauridae family. They had very long necks. Which is more than half of its total length (23ft to 38ft). This aquatic monster with its incredibly long neck, larger flipper-like limbs, and small head weight up to several tons.

They lived around the North American sea from 76 to 70 million years ago Companion of the Cretaceous period. Albertonets also had gastroliths that were 5 ½ inches in diameter. They helped to digest. Unchewed prey.

The most interesting thing about Albertonectus is their high bone density neck. There were 76 bones in their neck. No animal ever found had that much bone in the neck. This neck had helped them to collect shellfish from the seabed or capture fish and squids.

Sealord Thalassomedon

  • Species: T. haningtoni

Thalassomedonword came from ancient Greek which means sea lord. That makes sense because the Thalassomedon is a huge animal. The aquatic predator was 45ft long.

They could swim very effectively because of the 7ft flipper-like limb in their body. They were only 14 vertebrates behind Albertonectes in terms of neck bones with 62 vertebrates. The sea lord had a small 19-inch head but 2-inch long sharp teeth. Like Styxoaurus and Albertonectes their stomachs are full of stones.

Thalassomedonlived in Cenomania during the Cretaceous period. They were found in several locations in North America.

Monster of the shallow sea Tylosaurus

  • Genus: Tylosaurus; Marsh, 1872
  • Order: Squamata
  • Family: Mosasauridae

Tylosaurus belongs to the mosasaurs family which is a group that attained a high degree of adaptation to the aquatic environment and spread worldwide.

Huge chubby dolphin Shonisaurus

  • Family: Shastasauridae
  • Phylum: Chordata

The Shonisaurus lived in the late Triassic period 215 million years ago. The known location of their living in the united states especially in the Nevada-Luning formation.

These majestic creatures were 15ft in length and 30 tons in weight. Their body resembled a huge chubby dolphin shape.

Most marine reptiles had teeth for a strong bite but surprisingly Shonisaurus had no teeth. They had teeth at a young age but as they grow up teeth start to fall. Maybe because of the sheer size.
Blagest marine cornivour Masasaurus

  • Kingdom: Animalia
  • Genus: Mosasaurus; Conybeare, 1822
  • Class: Reptilia
  • Phylum: Chordata
  • Order: Squamata
  • Family: Mosasauridae

Masasaurus lived 65 million years ago in the Monstrichtion of the Cretaceous period. These 59ft the long aquatic monster is the biggest marine carnivore of its time. Crocodile shaped head with razor-sharp teeth gave it s
a terrifying look.

Found in Western Europe and North America also the Antarctic. Named after the Meuse River. They had pterygoid teeth anchored to its mouth.

Final boss Shastasaurus

Order: Ichthyosauria

Family: Shastasauridae; Merriam, 1895

The Shastasaurus lived 210 million years ago in the late Triassic period. It was the largest marine reptile at that time.

They have been found in the United States, North America, and china. 69ft long body with the weight of a blue whale (75 tons) made it a giant sea monster. But it was very slim compared to the length. It had a 6ft across the Ribcage.

That was ten Aquatic monsters around the Jurassic ages I hope you will find this helpful. stay with us.

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