The Cenomanian, about 99 to 93 million years ago
Spinosaurus lived in the early part of the Late Cretaceous, in the Cenomanian age, roughly 99 to 93 million years ago. Its world was warm, wet and dominated by great river systems across North Africa.
Long before T. rex
The famous Jurassic Park III fight is fiction for more than one reason. Tyrannosaurus rex did not appear until about 68 million years ago, near the very end of the age of dinosaurs, some 30 million years after Spinosaurus had already died out. They also lived on different continents.
How we date it
The ages come from the rock layers the fossils are found in. The Kem Kem beds of Morocco and the Bahariya Formation of Egypt are dated to the Cenomanian using the other fossils and minerals they contain, which pins Spinosaurus firmly to that window of time.