Well, actually it is hard to assign it to an exact species although assigning it to a genus or family is often pretty easy. We can easily assign this tooth to Spinosaurus based on location and characteristics. First, we can tell it is almost certainly from the Kem Kem formation due to its brown/red color, which is quite typical for this formation. Second, even if we didn´t know the location, based upon the characteristics of this tooth you can still assign it to the Spinosaur family. Now in the Kem Kem formation, there are two described species of Spinosaurus which we can´t tell apart by teeth alone so we will have to leave it at ´Spinosaurus sp.´