Their gait is estimated to be very slow, even slower than the gait of elephants. Based on their skeletal remains, it has been estimated that their weight ranged up to 50 tons.
Paleontologists speculate that their ribs were not connected to the backbones, but were attached to the skin in the stomach region. The ribs were thin and fragile, and probably supported the lungs and other internal organs.
The skull was very small, and they had small teeth which were present only on the anterior section of their jaws. Their neck contained about 15 vertebrae, and could be as long as 20 feet, and would weigh between 10 to 16 tons.
The braincases of these dinosaurs were small when compared to the size of the body. Their brains were the size of the human fist, and this probably explains as to why these dinosaurs are not considered intelligent.
The tails were very long and they approximately composed more than 80 vertebrae. There has been some speculation that the tail was used for defense and noise making purposes.
Their eyes were located on either side of the head and rather up the skull. This would have enabled them to see the enemies approaching from both the sides simultaneously. Smell was probably an important part too in smelling both the predators and food.
Like the eyes, the nostrils were also located way up on the skull almost at the center of the eyes and not on the muzzle. The reason behind this has not been established as yet.
Diplodocuses were herbivorous in nature. It is believed that they probably ate a lot of conifer plants because these were available in abundance during the Jurassic era. Some scientists speculate that the neck of these dinosaurs is so long because that could it to obtain plants foliage in forests.
They could also use their neck to reach ferns that grew in wet, swampy areas where they could reach because of their size and weight.
As their teeth were blunt, simple, resembled a pencil and were located only on the front of the mouth, they were probably used to strip the leaves off from the plants. Leaves and plants were swallowed as a whole, and there was no chewing involved.
Diplodocus also swallowed stones known as gastroliths which helped digest the tough plant materials. Because of their huge size, it has been speculated that these giant dinosaurs had to eat constantly when they were awake to stay alive.
It is believed that they inhabited the western half of the United States, as most of their fossil remains have been discovered in the Rocky Mountains, Montana, Utah, and Colorado.
It is also believed that Diplodocus lived in herds and moved from one forest to another after all the vegetation was exhausted. Their huge size and tail would have been an adequate mechanism to ward off predators, but living in groups must have also provided additional security from carnivorous dinosaurs like Tyrannosaurus Rex and Allosaurus.
From the fossilized evidence that has been obtained, it has been established that Diplodocuses did not lay eggs in a nest. Rather, the eggs were laid when the dinosaur was walking. It is also believed that these dinosaurs did not take care of their young ones, but there is no way of establishing this fact.