Giant dino was built to sink
The biggest meat-eating dinosaur that ever lived had special bones that helped it hunt underwater, according to a new study. Spinosaurus, which lived in what is now North Africa around 95 million years ago, was even bigger than the famous T. rex, growing to around 16 metres long. It looked quite different from most large dinosaur predators, with a long, narrow skull, crocodile-like jaws, a huge “sail” along its back and paddle-like back feet.
Scientists think Spinosaurus lived at least partly in the water because of its snapping jaws and the fact that fish has been found in its stomach. However, until now they’ve debated whether it was an actual swimmer or a fisher that stood in shallow water and snatched at prey that came within reach.
Researchers from the UK and the US thought they could learn more about the monster dino and its relatives by comparing their bones with some of today’s partly aquatic (water-living) animals, such as alligators, hippos and penguins. “Instead of trying to know as much as possible about the whole skeleton of Spinosaurus, we asked a simpler question,” explained Professor Roger Benson of the University of Cambridge. “What are the most obvious signs that an animal routinely swam?“Although Spinosaurus is known about from just a small number of bones, these revealed enough details for the scientists to prove that they were unusually heavy. Most large dinosaurs’ bones were light, with a spongy texture to reduce their weight, but Spinosaurus and its smaller relative Baryonyx had much heavier bones – a bit like those of living animals that spend much of their time in the water. The team think these bones had evolved so the animals wouldn’t float, allowing them to swim underwater as they hunted. Another related species called Suchomimus, however, had bones that were lighter, suggesting that it may have hunted by wading in pools or by shores but that it didn’t have to swim underwater to nab its next meal.