Could a Spinosaurus kill a Tyrannosaurus Rex?

Answer 1

Certainly not while they were alive. Spinosaurus lived in what is now North Africa, while Tyrannosaurus Rex lived in what is now western North America. But apart from the fact they lived thousands of miles apart, they were also separated by millions of years. Spinosaurus lived during the Early-Late Cretaceous period, approximately 112Ma to 97Ma while Tyrannosaurus Rex lived during the Late Cretacious period, approximately 67Ma to 65Ma. An Ma is a megaanum, a period of a million years. Thus Tyrannosaurus Rex died out approximately 65 million years ago.

Tyrannosaurus was a land predator but its status as apex predator or scavenger is the subject of much debate amongst scholars. However, we do have a complete Tyrannosaurus Rex specimen, FMNH PR2081 "Sue", which measures 12.3 metres, and 4 metres tall at the hips, with a mass estimated to be in the region of 6 to 7.5 short tons, although this is the subject of much debate. The largest skull measures 1.5m in length and may have weighed as much 9 metric tonnes, however some suggest the estimates are flawed and greatly over-exaggerated.

Although Spinosaurus is thought to be much larger, at 15m in length, there are no complete specimens available. The skull is estimated to be around 1.5m in length but, again, there is much debate over its weight, anything from 4.4 to 18.4 short tons. But until we find some limb bones and a complete skull there's no way to estimate its size or weight with any degree of accuracy.

The depiction of a fight between Spinosaurus and Tyrannosaurus Rex in Jurassic Park III is pure fantasy. Its ferociousness was largely based upon its size, which was grossly exaggerated for the movie, but Spinosaurus is thought to have been a piscivore, a fish-eater, rather than a land predator, mostly due to its elongated, crocodilian jaws. Although it may also have preyed on pterosaurs (flying lizards) there is no evidence to suggest it would prey upon another predator of similar size and strength.

But with such scant evidence available, it is not known for certain which of the two, had they ever confronted each other, would be victorious. By largest estimated size alone, Spinosaurus would probably win, but these estimates cannot be relied upon. A large Tyrannosaurs Rex might easily overwhelm a smaller Spinosaurus, for instance. But without a complete specimen, we can never know for sure which was the more powerful of the two. If I were a betting man, I'd probably side with Spinosaurus but I don't think it would be anywhere near as easy as the depiction shown in Jurassic Park III. Tyrannosaurus Rex would have felt Spinosaurus' approach well in advance and would have been far better prepared or (if the scavenger hypothesis is correct) would have probably avoided a confrontation altogether.