Camarasaurus

*Camarasaurus supremus*

* Timothy Bradley Artwork
* Robert F Walters Artwork

***Camarasaurus (ca·mar·a·saur·us)*** was probably the most common sauropod dinosaur of the Late Jurassic Morrison Formation in North America. This large, 25-ton plant-eater was strong and massive, with powerful legs, a strong neck and tail, and a rounded head. Deep pockets or chambers in the vertebrae (bones of the spine) of *Camarasaurus* lightened skeleton without giving up strength. It is also how the dinosaur got its name, which means "chambered reptile."

## Discovery

The first record of *Camarasaurus* comes from 1877, when a few scattered vertebrae were located in Colorado, by Oramel W. Lucas. The paleontologist Edward Drinker Cope paid for the bones, as part of his long-running and acrimonious competition with Othniel Charles Marsh (known as the Bone Wars) and named them in the same year. Marsh later named some of his sauropod findings *Morosaurus grandis* but most paleontologists today consider this to be a species of *Camarasaurus* [1]. Such naming conflicts were common between the two rival dinosaur hunters, the most famous being *Brontosaurus*/*Apatosaurus*.

It was not until 1925 that a complete skeleton of *Camarasaurus* was recovered, by Charles W. Gilmore. However, it was the skeleton from a young *Camarasaurus*, which is why so many illustrations of the dinosaur from the time show it to be much smaller than it is now known to be.

The Morrison Formation, along the eastern flank of the Rocky Mountains, is home to a rich stretch of Late Jurassic rock. A large number of dinosaur species can be found here, including relatives of the *Camarasaurus* such as *Diplodocus*, *Apatosaurus* and *Brachiosaurus*. However, camarasaurs are the most abundant of all the dinosaurs in the Formation. There have been a number of complete skeletons recovered from Colorado, New Mexico, Utah, and Wyoming.

A recent discovery was made in Old Snowmass, Colorado.

## Description

The most unusual features of *Camarasaurus* were on its head. The large jaw bones had strong jaw muscles, and the teeth were unusually large for a sauropod. They were as large as chisels, with sharp points that chopped the plants it ate. *Camarasaurus* probably fed on plants that were coarse and tough. Its relatives, *Apatosaurus* and *Diplodocus*, with their small weak teeth, probably ate soft, tender plants. With large eyes and nostrils, *Camarasaurus* was alert and active. Like other sauropods, it probably moved in herds. It lived in the arid and semi-arid open country of North America. One *Camarasaurus* pelvis from the Cleveland-Lloyd Dinosaur Quarry in Utah has huge grooves in the bones where an *Allosaurus* tore into the flees and gouged the bones. *Allosaurus* was its fiercest enemy, but and adult *Camarasaurus* was so much larger that it was seldom attacked. A complete skeleton of a juvenile *Camarasaurus* was excavated from Dinosaur National Monument in Utah. Such skeletons are rare. Perhaps young sauropods grew to adult size quickly, so there is little chance of finding them in the fossil record. One interesting twist of fate for *Camarasaurus* was that its head was mistakenly placed on the skeleton of *Apatosaurus* at the Carnegie museum of Natural History. The mistake was not fixed for 75 years.

## Classification

The scientific classification of *Camarasaurus*, using the Linnaean system, is given in the box to the upper right but, among palaeontologists, this method of taxonomic classification of dinosaurs is being supplanted by the cladistics inspired phylogenetic taxonomy. A simplified version of one possible branching evolutionary tree, showing the relationship between *Camarasaurus* and the other major groups of sauropods, follows:

```
Saurischia ("lizard hipped" dinosaurs)
 `--Sauropoda ("lizard feet")
    `--Diplodocoidea (which includes *Apatosaurus* and *Diplodocus*)

```

*Camarasaurus* is considered to be a basal macronarian, more closely related to the common ancestor of all macronarians than to more derived forms like *Brachiosaurus*.

The type species of *Camarasaurus* is Cope's original species, *C. supremus* ("the biggest chambered lizard"), named in 1877. Other species since discovered include *C. grandis* ("grand chambered lizard") in 1877, *C. lentus* in 1889, and *C. lewisi* (originally *Cathetosaurus*) in 1988.

## Paleobiology

There is a fossil record of two adults and a 12.2 meter long juvenile that died together in the Late Jurassic Period, (excavated in north east Wyoming, USA, by the Division of Vertebrate Paleontology of the University of Kansas Natural History Museum and Biodiversity Center, during the 1997 and 1998 'field seasons'). It is assumed that their bodies were washed to their final resting place, in alluvial mud, by a river in spate. This suggests that *Camarasaurus* traveled in herds or, at least, 'family' groups. Also, recovered *Camarasaurus* eggs have been found in lines, rather than in neatly arranged nests as with some other dinosaurs, which appears to suggest that, like most sauropods, *Camarasaurus* did not end its young. As for its digestion, some scientists had suggested that *Camarasaurus* and other sauropods may have swallowed stones to help grind the food in the stomach and then regurgitated or passed them when they became too smooth. However, more recent analysis of the evidence for stomach stones has suggested that this was not the case. Furthermore, the strong, robust teeth of *Camarasaurus* in particular were more developed than those of most sauropods, indicating that it may have processed food in its mouth to some degree before swallowing.

## JPInstitute.com Description

Camarasaurus was a very heavily built member of the long-necked sauropod family of Jurassic dinosaurs. It is very well known by scientists and recently a family of these large creatures was discovered in the Western U.S. Camarasaurus is also a part of one of paleontology's big mistakes when its head was put on the body of Apatosaurus and called Brontosaurus.

Compared to some of the other sauropods, Camarasaurus had a relatively short neck and tail. It also had a large head compared to other sauropods, but the head was almost hollow. The skull openings for the nose and eyes were very large. This is the most common North American sauropod found, with more than ten fairly complete skeletons unearthed to date. At least four species have been identified within this genus.

Camarasaurus gets its name from the hollow spaces in its neck vertebrae. These would have made the neck lighter and easier for the dinosaur to lift and move about. This dinosaur also had the largest teeth among sauropods.

## Dinosaur Field Guide Description

Camarasaurus. ("chambered lizard") is one of the most bulky of the sauropods, the big long-necked plant-eaters, It has teeth that are shaped like spoons, only much thicker. The head is large and boxlike, with powerful jaws and a wide bite. Camarasaurus fed on very tough, fibrous plants and, like all sauropods, did not chew food but swallowed it whole. This is why sauropods swallowed gastroliths, or stomach stones. The stones helped to grind up the plants inside their stomachs. The name Camarasaurus comes from the chambers that can be seen in its vertebrae. These hollow chambers serve to lighten the skeleton and give it strength. Some scientists believe that these chambers also housed an air-sac system similar to that in birds. Air sacs are part of the respiratory system and are connected to the lungs. This would have greatly helped the air flow through the lungs. Gigantic animals like sauropods would have benefited from a more efficient system of breathing, because carrying around over twenty-five tons of weight would require a lot of oxygen.

### Fun Facts

Camarasaurus is one of the very few dinosaurs for which juvenile skeletons have been found along with adults.

### Trivia

This dinosaur was part of the famous "Bone Warg" of the 1870s between Edward Drinker Cope and Othniel C. Marsh, two scientists who comlpeted to name the most dinosaurs.

## Appearance in other media

### *Jurassic Park*

* *Camarasaurus* appeared in the video game Jurassic Park: Operation Genesis.
* *Camarasaurus* appeared in the video game Jurassic Park Builder.
* *Camarasaurus* appeared in the video game Jurassic World: Evolution.

## Links

http://web.archive.org/web/20030216014910fw\_/http://www.jpinstitute.com/dinopedia/dinocards/dc\_camar.html#

## References

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1. ↑ Template:Cite book