Paleontologists Nizar Ibrahim and Paul Sereno are the scientists behind the discovery of Spinosaurus, the largest predatory dinosaur ever found. Described as "half duck, half crocodile," Spinosaurus is thought to have been semiaquatic and its discovery is forcing experts to rethink what they thought they knew about dinosaurs. We revisit our conversation with them.
The Spinosaurus aegyptiacus is known as one of the largest and longest theropod dinosaurs. Measured at about 50 feet in length, this massive creature is the only known dinosaur to adapt to aquatic life. It is predicted they would swim the rivers of North Africa and prey in regions consisting of mostly large fish. View a graphic on the Spinosaurus.
Despite similarities to the Tyrannosaurus rex, the Spinosaurus featured a narrow skull. Its skull was comparable to a crocodile's profile today. It was also studded with short but still relatively sharp teeth. Paleontologists believe the Spinosaurus speared fish out of the water because of the skull's shape and the dinosaur's location to the north African shoreline. View a graphic about the Spinosaurus's skull.
Spinosaurus was 9 feet longer than the largest Tyrannosaurus rex specimen known to man. The very prominent sail that sat atop the dinosaur was lined with tall neural spines growing on the back vertebrae. The lengths of the spines usually stretched 10 times the diameter of the vertebral body, and were usually longer at the front and backs than at the higher up middle.