Once again, it's me! In JP3, when the Spinosaurus kills T. Rex, i heard T. Rex died when it was bitten on the neck! Spinosaurus' teeth were common of it's family: Small, crocodile-like teeth best suited for hunting fish or small mammals and lizards! Plus when the plane crashes into Spinosaurus, it survives and destroys the plane! Spinosaurus coulden't have killed T. Rex with a bite to the neck, let alone crush a plane with it's teeth. They made Spinosaurus like a dino which wore armor and had surgical-steel teeth! Besides, the engine and propellers would badly hurt it, if not kill it! Plus, they show Spinosaurus swimming in the water. The only aquatic dinosaurs in the Mezozoic were the Hesperonis family! Spinosaurus is NOT as cracked up as JP3 makes it!
from Samuel C., age ?, ?, ?, ?; July 17, 2001

TOM: Well, although I agree that Spinosaurus had crocodile-like teeth, they were anything but small! The largest teeth known for Spinosaurus are almost as big as the largest teeth known for Tyrannosaurus. Also, although Spinosaurus probably hunted fish as a large part of its diet, those fish could be up to 10 feet (3 m) long. Futhermore, like modern Nile and estuarine crocodiles, Spinosaurus probably ate large land animals as well as fish.

So Spinosaurus might well have been able to kill T. rex, if it managed to get a good hold of the neck. However, this is something that could only happen in Jurassic Park, as they two dinosaurs lived 30 million years and an ocean apart!

I agree, however, that it is very unlikely that Spinosaurus would be able to crush a plane with its jaws!! They, like all dinosaurs, were just flesh and bone.

Although Hesperornis was the only FULLY aquatic dinosaur we know about in the Mesozoic, most dinosaurs could probably swim to one degree or another. After all, even horses can swim and horses are built almost exactly the opposite of the way a good swimmer is built (horses have long skinny legs with small rigid hooves instead of shoter powerful legs with broad flipper like feet). So Spinosaurus probably could swim, but probably not as well as shown in the movie.