Great vid. Wanted to note though: Diseases don't evolve to some perfect state of infection. Many diseases become less lethal over time to enhance their survivability. The T-rex has not been an environment for diseases to infect for so long of a time, that its possible no disease in the modern era would infect it, because any t-rex specific disease died out with them. Sort of like how an animal can get sick without you getting sick. Having said that, it is also possible that some diseases, especially in chickens or reptiles, would be able to adapt to the T-rex and begin infecting, though I doubt the effects would be so quick. None of this is meant as critique, merely expanding on.