Writing a fight scene. And who doesn't love a good fight?

This time the ring goes out into the depths of the sea to pit two of the most powerful predators to ever swim the seas to tussle in the tides. "Dino" in quotations as, since there are no penguins or Spinosaurids about and since we're talking aquatic animals, there are no dinosaurs to be had here. Instead our contenders are arguably the largest predatory reptile and mammal to ever exist and from opposite sides of the Cretaceous-Tertiary boundary.

It's a clash between two very different skill-sets. On one side, the massive gape, maneuverable body, slashing fangs, and multiple jaws of the serpentine Mosasaurus. On the other, the massive fangs, crushing jaws, and sonar of the bulky Livyatan. Would the age of reptiles have a serious challenger amongst the suppressed mammals if their titanic descendant from 50 million years later arrived early? Or would the scaly, ferocious, slithering form with rending teeth carve the mammal to shreds? The winner of this match up takes on Megalodon in a future contest for the crown of Monarch of the Seas!

Species:Mosasaurus hoffmannii ("Hoffmann's Meuse River Lizard")
Family: Aquatic Varanid ("Monitor") lizard
Length: 17 meters (55 feet)
Weight: 20-25 tons

Species: Livyatana melvilli ("Melville's Leviathan")
Family: Toothed Cetacean ("Dolphins" and "Sperm Whales")
Length: 16 meters (52 feet)
Weight: 60 tons

And, as a little tie-in to some popular culture, this will also be the first death match to have two possible rounds. If Livyatan manages to churn out a win against the Mosasaurus, it'll go up against this bruiser!

Species:Mosasaurus ingens ("InGen's Meuse River Lizard")
Family: Aquatic Varanid ("Monitor") lizard, genetically engineered
Length: 25 meters (82 feet)
Weight: 30 tons

Since the Mosasaurus is faster and agiler, and the Livyatana is slower and heavier, I recommend the Mosasaurus would win the fight.

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I take in a lot of research before publishing the result, but do feel free to vote in the poll or send me research that might be relevant!

Which Mosasaur by the way?

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Which Mosasaur by the way?

The real version.

As much as I want to say Mosasaurus would win, the extra bulk probably tips the scales more into Livyatan's favor. If it was a JW Mosasaur instead of an IRL one however, THAT would be a very different story.