Supersaurus looks like almost any other sauropod, what makes it so radically different is the length of this behemoth. The Apatosaurus weighs in at around 25 tons and 75 feet; a very long and heavy dinosaur by any means and an enormous land animal. Supersaurus dwarfs its cousin at over 40 tons and 116 feet. Why would an animal need to get larger than Apatosaurus? For one, food niches in the environment. What an Apatosaurus cannot reach with its long neck, either up in the trees or down along the ground just inside the reaches of a forest, say, are easy pickings for Supersaurus. Additionally, with a longer and equally whip-like and therefore potentially deadly tail, Supersaurus was much more of a threat to the predators of its time. If Allosaurs only hunted Apatosaurs in packs on account of their size and tail, the pack of hunters taking down Supersaurus would have had to have been even more wary at greater distance from the prey's vital parts.
Any predator attacking an animal like Supersaurus, such as this foolish Allosaurus, are going to get hurt. That tail is not the only weapon available to a dinosaur that large. Just the sheer bulk of this animal is deadly. Here, this animal in Rey's illustration is clearly large, but I would venture to say that it does not look to be a fully grown Supersaurus based upon the fact that the proportions in relation to the Allosaurus are not large enough. Surely it cannot be debated that this sauropod is tossing an Allosaurus bodily into the air with its front legs, but it does not seem to tower over it enough to be an adult. Look at his head also. For a sauropod it seems as though Supersaurus had a rather large head relative to his overall body size. Typically when we think of or look at sauropods we see extremely tiny heads in relation to their body size. In some illustrations this is also the case for Supersaurus. However, it is not always the case in all ages of this animal and therefore not in all illustrations. This head size is further fuel for the idea that this specimen of Supersaurus is not a fully grown adult but is actually a mostly grown juvenile who still has a summer or so ahead of her before she is fully grown. Supersaurus did, however, have a larger skull regardless of the individual's age, relative to body size, than did Apatosaurs and Diplodocids. Also here, notice the inside fifth digit on the forepaws of this sauropod and how they are bent inward as sinister looking claws for defense mostly.
The last image I want to use today (permission pending but it's here for now at least granted) is of two Supersaurus having a slight argument. The illustrator states that the two are an older and younger male fighting over mates. Regardless of the material of the fight I want to use this to show how dangerous these animals were to each other as well as how dangerous they were to other species. The tail, for example, is thin and sharp when cracked the right way against another individual. That tail, much like the whips humans have used for centuries in one capacity or another, could probably have opened up another animal at lightning speed and caused sever damage to the skin and underlying muscles as well. The other danger, as discussed, is, of course, the size of the animal. The weight of one of these animals driving in the fifth digit spike on the forepaw or even just pounding on another dinosaur with its weight would have been enough to cause most animals to yield and turn away from another Supersaurus. As we see in modern giraffes, I wouldn't be amazed if these dinosaurs also used their necks in fights. Surely they must have bit and nibbled at each other as well as a way to end a fight without the wrestling antics of slicing each other up with that tail. We may never know for certain, but that's okay, we have imagination, evidence, and common sense to figure it out.