Suchomimus tenerensis, a large Spinosaurid Theropod from North-Eastern Africa during the early mid-Cretaceous. It's anatomy and skull suggest it was an active aquatic predator. It's skull and jaws were long and narrow like that of a crocodile, leading palaeontologist Paul Sereno to describe it as, "A dinosaur trying very hard to be a crocodile."
The Middle and Late Jurassic Periods were a time in which the dinosaurs took over the world. This is also the time period when Pangea broke apart, which separated many species of dinosaurs. (Check out the 23 dinosaurs I posted individually.)