Thankfully, according to experts, T-rex's were indeed able to swim in real life. As is explained in Apple TV+'s Prehistoric Planet , marks known as "swim traces" have been found on fossils of T-rex's.

As the T-Rex picks apart the powered-down fence, it escapes the paddock and lets out a bone-chilling roar that sets the tone for the rest of the scene. The T-Rex’s roar is certainly up there ...