Spinosaurus (IMAGE) University of Portsmouth Caption Spinosaurus, the longest predatory dinosaur known, is opening its elongate jaws, studded with conical teeth, to catch a sawskate. Contrary to previous suggestions, this animal was not a heron-like wader - it was a "river monster", actively pursuing prey in a vast river system located in modern-day North Africa. Dense bones in the skeleton of Spinosaurus strongly suggest it spent a substantial amount of time submerged in the water. Credit Artwork credit: Davide Bonadonna Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.