Camarasaurus, meaning “chambered lizard” (chambered referring to holes in its vertebrae), was a genus of quadrupedal, herbivorous dinosaur from the Late Jurassic Period 155 to 145 million years ago. It was first found in 1877 when a few scattered vertebrae were discovered in Colorado by Oramel W. Lucas. The bones were sold to Edward Drinker Cope and named by him later that year. A more complete fossil was discovered in 1925 by Charles W. Gilmore. The Morrison Formation, along the eastern Rocky Mountains, is home to a large number of dinosaur remains. The Camarasaurus is the most abundant of all remains found here. Many complete skeletons have been recovered from the formation in the states of Colorado, New Mexico, Utah, and Wyoming.
Camarasaurus was the most common of the giant sauropods found in North America; however, it was only average in size at about 60 feet in length as an adult. It weighed up to 20 tons. The arched skull may have contributed to the name “˜chambered lizard’. It was remarkably square with a blunt snout. It was a sturdy skull, and is often recovered in complete and good condition by paleontologists. The teeth were 7.5 inches long, shaped liked chisels, and aligned evenly along the jaw. The strong teeth indicate that it most likely ate tough, coarse plant matter.
Each of its giant feet bore five toes. The inner toe on each foot had a large sharpened claw for self-defense. Like most sauropods, the front legs were shorter than the hind legs. However, the high shoulders meant there was little slope in the back. It is suggested that due to lack of upward projections on each of its vertebrae, Camarasaurus was not able to raise up on its hind legs. The vertebrae were otherwise specialized for weight reduction as they were hollowed out as in most large sauropods from later periods. Like elephants, the Camarasaurus had a spongy wedge of tissue at the base of the heel, which helped support its heavy weight. Its neck and tail were shorter than normal for a sauropod of its size. There was an enlargement in the spinal cord near the hip area, which suggests to some scientists that it may have had a second brain to possibly help coordinate such a large beast. There is debate over the topic and most scientists today believe it was an area of a large nervous system, and not necessarily a brain. However, the enlarged area was a lot larger than the small brain contained in the animals’ skull.
Like many birds, some sauropods such as Camarasaurus swallowed stones to help with digestion of the rough plant food. It either regurgitated or passed the stones when they became too smooth, though this method is debated. The strong teeth of this specimen indicate that it may have processed its food in the mouth before swallowing it. It is suggested that Camarasaurus traveled in herds or family groups as many remains of individuals are found in one area. Camarasaurus eggs have been found in lines, rather than neatly arranged nests, which indicate that it may not have tended to its young.