Daily Mail: ‘Underwater T-Rex’ – New Monster Species Found Off South Africa That Makes Sharks Flee

Sensational headlines claiming a new “Underwater T-Rex” discovered off South Africa that terrifies sharks are classic tabloid exaggeration. No dinosaur ever lived in the sea, and no such creature has been found.

What the story almost certainly refers to is a new or newly described mosasaur (or possibly a large plesiosaur) from Late Cretaceous marine deposits along the South African coast. These giant marine lizards—unrelated to dinosaurs—were the true apex predators of the Cretaceous oceans and could reach 10–15 metres. Some species, such as Tylosaurus or Mosasaurus, possessed serrated teeth and bite forces powerful enough to prey on sharks, turtles, and other marine reptiles.

Any fossil recovered from the seabed off South Africa would have been preserved in ancient shallow marine or coastal sediments of the Agulhas or Natal regions, not deep ocean. Like all “marine dinosaur” stories, the bones reached the seafloor through normal post-mortem transport by rivers or coastal currents, followed by millions of years of burial.

The dramatic claim that sharks “flee” from it is pure hype. While these reptiles were formidable hunters, they coexisted with large sharks in the same ecosystems; both groups competed at the top of the food chain until the end-Cretaceous extinction.

From the waters off South Africa, the real story is the incredible diversity of Mesozoic marine reptiles—not dinosaurs invading the oceans. Paleontology continues to reveal terrifying predators of the ancient seas, but the “Underwater T-Rex” remains firmly in the realm of fiction.