Pliosaurs – Marine dinosaurs were twice as large as killer whales

Until now, pliosaurs were assumed to have been about six meters long. A serendipitous find from a museum now shows that marine dinosaurs were much larger and dominated the oceans.

Portsmouth (England). In science, it was previously assumed that Liopleurodon, a genus of pliosaurs, reached a maximum length of about six metres. In the BBC documentary series Walking with Dinosaurs, it was shown that Liopleurodon was about 25 meters long. This representation has been criticized by many experts as exaggerated.

researchers University of Portsmouth David Martell recently made an accidental discovery at the Abingdon County Hall Museum that the sea-dwelling dinosaur could reach 14.4m in length, twice the size of the killer whale. In fact, Liopleurodon wasn’t as big as Serial, but much larger than research has previously suggested.

“I was a consultant on the BBC Pilot Program and I admit I was completely wrong when I came to the size of Liopleurodon. I based my calculations on fragmentary material indicating that Liopleurodon could be up to 25 meters long, but the evidence was weak and there was a lot of controversy at the time. It was The BBC’s 1999 size estimate is overstated, but now, thanks to a happy discovery, we have four giant whirlpools that provide even more reliable evidence.”

Pliosaur vertebrae have been discovered

According to what was published in the specialized magazine Proceedings of the Society of Geologists Researchers accidentally discovered a large vortex at the Abingdon County Hall Museum. Then the curator turned her attention to three more main vortices. The vertebrae can be clearly identified as close relatives of Pliosaurus or a similar animal. Pliosaurs were like plesiosaurs, but had a larger, crocodile-like, elongated head and a shorter neck. They had four flippers that acted as powerful paddles to propel them through the water, and a relatively short tail.

The whirlpools were originally discovered during temporary excavations at Warren Farm in the Thames Valley in Oxfordshire and are of the Kimmeridge Clay Formation. This deposit dates back to the late Jurassic period and is about 152 million years old.

Topographic scans reveal volume

After topographic surveys, the researchers estimated that this late Jurassic marine reptile could reach between 9.8 and 14.4 meters in length.

“We know that these plesiosaurs were very fearsome animals that swam the seas that covered Oxfordshire 145 to 152 million years ago. They had a massive skull with huge teeth protruding like daggers, as large if not larger than a T-rex, and certainly more powerful.”

Pliosaurs dominated the oceans

Researchers believe that pliosaurs likely dominated the oceans, feeding on small marine crocodiles and ichthyosaurs. They bit their victims with such force that they literally cut them in two and then ate them piece by piece. Today, these hunting methods can still be traced using bite marks on ichthyosaur bones.

“It is remarkable that a truly gigantic species of Pliosaurus existed in the late Jurassic seas. Although we are not yet quite on par with the claims made about Liopleurodon in the popular BBC TV series, it wouldn’t surprise me if we someday find clear evidence that this species The wild one was bigger.”

Proceedings of the Society of Geologists, doi: 10.1016/j.pgeola.2023.04.005