MOSASAURS: APEX MARINE PREDATORS

A Mosasaur Snatches a Tasty Bite

Slip beneath the surface of a Late Cretaceous ocean—if you dare—and you enter the domain of one of Earth’s most spectacular marine predators: the mosasaur. 

Long before whales ruled the deep, these muscular, paddle-limbed lizards patrolled warm inland seas with the confidence of creatures that knew nothing could challenge them for long.

Imagine a body built like a torpedo, jaws hinged like a trap, and teeth designed for the dual purposes of slicing and holding. Some species stretched over 15 metres long—longer than a city bus—yet they moved with the agility of oversized crocodiles on turbo mode. 

With a powerful tail fin beating side to side, they could lunge forward in explosive bursts, swallowing ammonites whole or ambushing unsuspecting sharks. Yes—sharks were on their menu.

Scientifically, mosasaurs are a wonderful paradox. They were reptiles—close cousins of modern monitor lizards—but they evolved flippers, streamlined skulls, and even tail flukes remarkably similar to those of whales and ichthyosaurs. Convergent evolution at its flashy finest.

Mosasaurs hunted in our Cretaceous Seas

Their fossils also tell a tale of planetary drama. The chalky cliffs of Europe, the badlands of Morocco, the ancient seaways of Kansas—all hold the remains of these sea dragons. 

Every jawbone and vertebra is a relic from a vanished ocean that once split North America in two.

Along the rugged shores of Vancouver Island, mosasaurs left their mark as well. 

In the Nanaimo Group—marine deposits laid down in the twilight of the Cretaceous—researchers have uncovered beautifully preserved remains that once cruised the ancient Pacific coastline. 

Species recorded from these rocks include Tylosaurus pembinensis, Plioplatecarpus marshii, Mosasaurus hoffmanni, Clidastes liodontus, and the smaller but no less impressive Phosphorosaurus ponpetelegans. 

These fossils, often found in shale and sandstone, offer a rare West Coast window into the last great age of marine reptiles.

And yet, their spectacular reign was brief. When the asteroid struck 66 million years ago, the seas dimmed, the food chains collapsed, and even these titans couldn’t outswim extinction.

But in stone, they still roar. Their skeletons—sleek, predatory, impossibly elegant—remind us that Earth’s oceans were once ruled by lizards the size of whales… and that nature occasionally writes stories no novelist would dare invent.