Without a time machine we can only make analogies with living animals to conjecture about the habits and behaviour of extinct creatures. We have only found remains of spinosaurus in Africa and T-rex in North America. Moreover, they were separated in time by as much as 30 million years, so they would never have actually come face to face with each other.
But what if we could have arranged a meeting between these two superdinosaurs? Both animals were undoubtedly very powerful flesh eaters. In both, a large skull with an array of dagger-like teeth was the principal weapon. However, T-rex had a more robust skull and probably the more powerful bite of the two. The narrower, more elongated snout of spinosaurus suggests a quicker but less powerful bite. Resembling a crocodile’s snout spinosaurus may well have been better adapted to fish eating. While my vote goes with T-rex, in reality both would have been wary of each other and avoided fighting.
Answered by Nick Fraser, Keeper of Natural Sciences, NMS.