About Camarasaurus
| Scientific Name (Genus) | Camarasaurus |
| Meaning of Name | Chambered lizard kamara (chamber) [Greek] - saurus (lizard) [Greek] |
| Classification | Saurischia, Sauropodomorpha (Sauropoda) |
| Total Length | Approx. 15-23m |
| Diet | Herbivorous |
| Period | Late Jurassic (approx. 155-145 million years ago) |
| Species | Camarasaurus grandis Camarasaurus lentus Camarasaurus lewisi Camarasaurus supremus |
| Year of Paper Publication | 1877 |
| Genus Name Publication | Cope, E. D. (1877). On a gigantic saurian from the Dakota eopoc of Colorado. Palaeontological Bulletin (25). |
Characteristics
Camarasaurus was one of the most prosperous sauropods in Late Jurassic North America.
Its total length was 15-23m, with an estimated weight of 20 tons, though it was not particularly large for a Late Jurassic sauropod.
Fossils of adults and juveniles have been found together, suggesting they may have lived in herds.
The habitat of Camarasaurus was also home to the formidable theropod Allosaurus, giant sauropods like Diplodocus and Brachiosaurus, and the stegosaur Stegosaurus. Camarasaurus fossils with bite marks believed to be from Allosaurus have been found, illustrating the harsh struggle for survival at the time.
It has a shape called a 'spoon-type'. It was thicker and stronger than that of Diplodocus.
The teeth of Camarasaurus were thicker and stronger than those of Diplodocus. A 2006 publication revealed that their teeth were replaced every 62 days on average.
Like other sauropods, stones (gastroliths) to aid digestion have been found in its stomach, but the strong teeth that were replaced so frequently suggest it may have eaten tougher plants or even chewed (masticated) vegetation in its mouth.
Each of its massive feet had five toes, and the inner toe had a large, sharp claw for defense.
Skeletal fossils from various growth stages have been excavated, helping us understand the ecology of sauropods.
The Long-Distance Migration of Camarasaurus
The Morrison Formation in North America, where Camarasaurus lived during the Late Jurassic, was a vast floodplain with a semi-arid climate characterized by distinct dry and wet seasons.
In 2011, the University of Colorado announced the results of a study analyzing Camarasaurus tooth fossils.
They found that "Camarasaurus migrated long distances of about 300 km seasonally each year."
How can evidence of long-distance migration be found in tooth fossils?
Camarasaurus replaced its teeth approximately every five months. The research team focused on the "different ratios of oxygen isotopes in highlands (mountainous areas) and lowlands (plains)" and the "tooth replacement period." Higher elevations tend to have lower levels of oxygen-18. When Camarasaurus drank water, oxygen isotopes were incorporated into its body and formed the enamel of its teeth. The researchers investigated the change in the ratio of oxygen isotopes in about 30 tooth fossils.
The results showed that the ratio of oxygen-18 was completely different between the root and the crown of the teeth.
This indicated that Camarasaurus had moved between highlands (mountains) and lowlands (plains) within a five-month period.
It is highly likely that they left the lowlands during the dry season when food plants were scarce and moved to the plant-rich mountains, returning to the lowlands when the rains came.
The Bone Wars of Cope and Marsh
In 1877, Oramel W. Lucas, a local schoolteacher in Colorado, discovered fragmentary vertebrae fossils.
Source: Cope, E. D. (1877). On the Vertebrata of the Dakota Epoch of Colorado. Proceedings of the American Philosophical Society, Vol. 17, No. 100.
Edward Drinker Cope purchased these fossils and described Camarasaurus in the same year, 1877.
Othniel Charles Marsh also described a new sauropod genus and species, Morosaurus grandis, in the same year, but it is now considered a species of Camarasaurus.
Subsequently, a series of well-preserved fossils were discovered, and in 1925, Charles W. Gilmore reconstructed a highly accurate Camarasaurus.
Although Edward Cope named the genus Camarasaurus, both Cope and Marsh are credited as authors at the species level.
| Year | Author | Species Name |
|---|---|---|
| 1877 | Edward Cope | Camarasaurus supremus |
| 1877 | Othniel Charles Marsh | Camarasaurus grandis |
| 1889 | Othniel Charles Marsh | Camarasaurus lentus |
Topics
An actual Camarasaurus skeleton is on permanent display at the Gunma Museum of Natural History, and a skull fossil is at the National Museum of Nature and Science in Ueno, Tokyo.
In 2008, a companion (pet) robot named
The model for the 30cm long, 1.5kg robot
Camarasaurus Stamp & Fossil Gallery
