Scientists believe that this aquatic dinosaur was the largest predator to ever roam the planet. | National Geographic

Spinosaurus was one of the largest carnivorous dinosaurs, reaching up to 18 meters (59 feet) long and weighing around 9 tons. Unlike most theropods, it likely spent much of its time in the water, using its long, crocodile-like snout and conical teeth to hunt fish. Its massive sail, formed by tall spines on its back, may have been used for display or temperature regulation. Recent studies suggest it was a strong swimmer with dense bones, paddle-like feet, and a flexible tail. However, some resear