I imagine how it would be a hypothetical struggle of two prehistoric animals from different eras. The largest land mammal "Paraceratherium" against the largest carnivorous dinosaur, the "spinosaurus". All this is pure speculation this confrontation never happened, these animals the time and space are separate.
Dimensions suggest that spinosaurus was 4.5 meters high in the head, about 6 meters on the tip of his dorsal sail, 14 meters long on average (tip of snout to tip of tail), and 9 tons mass. The of Paraceratherium dimensions, had a height of five meters on the cross, 7 meters in the head, and eight meters long (excluding the tail). Estimates of the weight of this creature vary but oscillate about fifteen tons.
But here's the question: What would happen if a spinosaurus would face a Paraceratherium?, Since the latter is a prehistoric rhinoceros the size of a medium-sized sauropod. The Spinosaurus is able to hunt small fish or fight with rivals as big as the reptile itself, was used to fighting against others of the same species for territory. This predator could have lived with some sauropods that were larger and better protected than a Paraceratherium and therefore is likely to have an idea of how to fight this herbivore. While never the Paraceratherium could find any predator even half as big as the spinosaurus.
I do not think this theropod trembles of fear with such opponent, but would be reluctant to attack big prey. Extrapolating with the present, the lions rarely attack the giraffes or elephants, as is more safer for them attack smaller prey. However, when they are hungry enough, sometimes they are attacking the giraffes and elephants, but to young animals and always in group.
An animal can have the size and strength, as the Paraceratherium, but has the instinct of a hunter, like the spinosaurus?, They are not stupid animals. Even a crocodile's brain is the size of a golf ball has the ability to knock down most of the savannah animals. Therefore, this carnivore if hunger had enough, I'm sure that would make the attack.
What have the Paraceratherium, for attack and defend? I think it would be able to hit using his neck like a giraffe but it does little damage to your opponent and his long neck would be exposed to the fatal bite of this foe. The best weapon would be the kicks like the rest of the herbivorous quadrupeds, could take him down, breaking some ribs and seriously injure the predator. In this scale, if he fell on his back the dinosaur could have died because of breaking his sail, and which would give him the victory. In this prehistoric rhinoceros his teeth seem interesting, as if he were about to change independently fangs.
But the force of the bite, may be useful? I think they were most needed to detach the leaves from the trees, but not enough long and sharp to attack the opponent. I think those teeth could cause significant damage if used correctly. Rhino skin is a good defense it is hard and thick to wounds critical avoid of this large carnivore . The downside is its weight (over 12 tons) makes it slow, so I rather doubt about his agility. Strike and run I think would be the best tactic for him.
The spinosaurio has weapons designed to kill fish, his jaw is adapted for grasping slippery prey, his neck is not appropriate for to violent movements which shake and tear, his manner eating is of swallow his prey whole.
Speculated this theropod would not be stupid enough to approach this hornless rhinoceros behind, and is agile enough to avoid his kicks. So the spino could have the advantage if used the bite in the neck to cause much damage, could also catch him with his arms that were much larger and muscular than the Tyrannosaurus.
The strength of is very serious bite of 3 tons at the tip of each tooth, rapidly so penetrate through its skin and cut off many vital blood vessels, then the animal loses a lot of blood to death. I can assume that if the first bite does not work, will continue to attack in this way until you achieve your mission, not waiting there after a bite, by what the victim has not been defeated yet.
In that case, the dinosaur has a very good chance of winning, since these taticas allows you to avoid injuries and cause massive damage at once. Finally I think the giant reptile with its fatal bite could inflict incredible wounds in the herbivore , the theropod would be too fast for the mammal try again to recover. In conclusion in this hypothetical fight, the spinosaurio is the winner.