Saturday, November 19, 2016


Camarasaurus was a genus of quadrupedal, herbivorous dinosaurs. It was the most common of the giant sauropods to be found in North America. Its fossil remains have been found in the Morrison Formation of Colorado and Utah, dating to the Late Jurassic epoch (Kimmeridgian to Tithonian stages), between 155 and 145 million years ago.

Camarasaurus presented a distinctive cranial profile of a blunt snout and an arched skull that was remarkably square. It likely travelled in herds, or at least in family groups.

The name means “chambered lizard”, referring to the hollow chambers in its vertebrae (Greek καμαρα/kamara meaning “vaulted chamber”, or anything with an arched cover, and σαυρος/sauros meaning “lizard”).

When the noted American paleontologist Edward Drinker Cope described Camarasaurus in 1877, he was obviously impressed by the hollow, box-like vertebrae in the neck. This feature made the neck much lighter and easier for the animal to carry, and it is this characteristic that gave the animal its name: “Chambered lizard.”

Camarasaurus was a stout, compact sauropod with a relatively short neck and short tail. The front legs were slightly shorter than the back legs. The head can be described as a bubble of air encased by thin struts of bone. Huge holes for the nostrils, eye sockets, and other skull cavities made the skull as light as possible but strong enough to withstand the bite forces from the doglike snout.

Camarasaurus supremus (#1) bones being exvataed by Oramel Lucas for Edward Drinker Cope, c. 1877.

The teeth were stumpy but strong – much more robust than the peglke teeth of other sauropods – and the jaws had a powerful bite. Camarasaurus was probably capable of dealing with a wider variety of tough plants, thereby giving it an advantage in mixed forests.

Camarasaurus is the most common sauropod in North America. A number of complete skeletons have been recovered, as well as numerous partial skeletons and isolated bones. Several specimens can be seen in the rocks of the dinosaur National Monument in Utah. As a result of these fossil finds, we now know more about Camarasaurus than we know about any other of the sauropod dinosaurs.

Fossil specimen in the Natural History Museum of Utah, Salt Lake City, Utah, USA. Photography was permitted in the museum without restriction. Author: Daderot