Nodosaurus probably has the least information available. This dinosaur is named after the bump like form of the armor it flaunted, which was bone plated. Nodosaurus was classified in 1889 on the basis of the remains discovered in Wyoming, Kansas and New Mexico. It is believed that the Nodosaurus existed between 70 and 110 million years ago, in the Cretaceous Period. It is interesting to note that Hierosaurus was reclassified as Nodosaurus.

Nodosaurus has been easily confused with other nodosaurids. The dinosaur Nodosaurus is believed to have been around 5.50 m in length. It was a four legged, plant eating dinosaur. Nodosaurus had a beak, without any teeth and was very similar in appearance to the other well-known herbivorous dinosaurs of the time. Nodosaurus had a short neck and legs.

It is also believed that Nodosaurus would take the 'crouch' position when threatened. This would leave the predator with nothing! This is because all that would be present in this position was a formidable armor. The armor plates are speculated to have weighed nearly 30 kg. It is possible that Nodosaurus could have had shoulder spikes or side spikes. It was smaller than the Panoplosaurus, in both, size and brain mass.