The biggest dinosaur predator that ever stalked the Earth was also the weirdest.

Scientists announced on Thursday the discovery in Moroccan desert cliffs of new fossil remains of Spinosaurus aegyptiacus, a 15-meter-long, 7-ton African monster that breaks the mold for how a dinosaur predator looked and behaved.

It was roughly 2.5 meters longer than Tyrannosaurus rex and equally massive. Living 95 million years ago during the Cretaceous Period, Spinosaurus also is the only known dinosaur adapted for a water-loving, semiaquatic lifestyle, the study found.