There are several contenders. So-called "Ultrasaurus" may have passed 100 tons. He was sort of a Brachiosaurus on steroids, but he's known only from a single massive thighbone. Then there's Seismosaurus ("earthquake-causing dinosaur") and "Supersaurus."
New bones are still being discovered and animals inferred from them. As we learn more about dinosaur physiology, it will be possible to predict a maximum possible size beyond which no dinosaur could grow.
The Sauropodomorphs dinosaur was the largest of the prosauropod dinosaurs.
The most tallest and strongest plant eating dinosaur was the Argentinosaurus. It was believed to be the largest land animal which had ever lived.
Fossilized dinosaur dung has been found that is quite large.
The large carnivorous dinosaur in Jurassic Park 3 was a Spinosaurus. It is thought to have been the largest terrestrial carnivore of all time.
The largest dinosaur is Amphicoelias, at 200 ft long.
Apparently, Argentinosaurus is the largest dinosaur discovered so far. There is always a chance that an even larger dinosaur may be discovered - so updating the current accepted dinosaur facts.
Triceratops
There are quite a few dinosaurs that could be considered large. The largest is probably Argentinosaurus, at over 120 feet long. Mamenchisaurus was quite big, too. It DID have the longest neck of any dinosaur. 4 other giant dinosaurs are Brachiosaurus, Seismosaurus, Mapusaurus and Paralititan.
The crocodile/alligator
The largest dinosaur name is Micropachycepahalosaurus. The shortest is Minmi.
It is difficult to know exactly which dinosaur had the largest heart. It is generally agreed upon that the Barosaurus had the largest heart, weighing more than two tons.
The Dinosaur.