Camarasaurus
KAM-uh-ruh-SORE-us
"chambered lizard"
- Lived
- 155 to 143 million years ago, Late Jurassic
- Diet
- Herbivore
- Length
- about 18 m (59 ft)
- Group
- Sauropods, Camarasauridae
- Found in
- United States
- Named by
- Cope 1877
Size comparison
To scale
Scale in meters
Where its fossils were found
The evidence
Today
150 million years ago
Also reported from Portugal.
Habitat
Rivers, wet floodplains and seasonal pools shaped its world in the Morrison Formation. Stegosaurus, Apatosaurus and Barosaurus were regional neighbors.
Field notes
About Camarasaurus
What it was like
Camarasaurus was a bulky, long-necked plant eater with a proportionally large, strongly built skull and powerful jaws. It grew to about 18 meters (59 feet) long. Its spoon-shaped teeth were rapidly replaced as they wore down from feeding on tough plants.
Its name refers to hollow chambers found inside the vertebrae of its neck and back, which likely made its skeleton lighter without losing strength. Camarasaurus is the most common dinosaur found in its main fossil-bearing formation, and one of the best understood sauropods.
Its world
Camarasaurus lived across what is now Wyoming, Colorado, Utah, New Mexico, South Dakota, and Montana, from about 155 to 143 million years ago, during the Late Jurassic, with possible finds also reported from Portugal. Its fossils come mainly from the Morrison Formation.
It shared its floodplain habitat with the plated Stegosaurus and Dacentrurus, the long-necked Brachiosaurus, Brontosaurus, Diplodocus, and Apatosaurus, and the predator Allosaurus.
How it was found
Cope named Camarasaurus in 1877, from fossils found in Colorado. About 124 finds of the genus are known today, more than any other dinosaur from the Morrison Formation, including several nearly complete skeletons.
Field gallery
More views of Camarasaurus
Scenes reconstructed from the available fossil evidence.
1 of 7
Lived alongside
Found in the same rock formations
A rock formation can hold fossils laid down millions of years apart, so not every animal here met Camarasaurus.
The evidence
The science behind Camarasaurus
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- Skulls and nearly complete skeletons show a robust body, a stout neck and a short, deep head.
- Broad, spoon-shaped teeth wore down while feeding, and replacement teeth developed inside the jaws.
- Its neck and back vertebrae contain hollow chambers that helped lighten the skeleton.
Borrowed from relatives
- Almost the whole skeleton is known from its own fossils, so little of the basic body shape needs to be borrowed.
- A scaly covering follows skin impressions in other sauropods, including Diplodocus.
Still unknown
- Its color and the full pattern of its skin.
- Which plants made up most of its diet.
- How much skull variation reflects growth, different species or differences between individuals.
Often drawn wrong
- Its head was short and deep, rather than the long, low skull of Diplodocus.
- Its forefeet were compact and upright, with at most a small inner thumb claw rather than spreading clawed fingers.
Discovery timeline
- 1877Named itCope
- 1925Full descriptionGilmore
- 2011Its worldFricke, Hencecroth & Hoerner
- 2021SkullWoodruff et al.
Key papers
The research behind what we know of Camarasaurus
Named it
Named Camarasaurus from bones found in Colorado, drawing attention to the chambers inside its vertebrae.
On a gigantic saurian from the Dakota epoch of Colorado. Paleontological Bulletin 25: 5-10
No link available
Full description
Described a nearly complete young skeleton with its bones still joined, providing a detailed account of the skull, limbs and backbone.
A nearly complete articulated skeleton of Camarasaurus, a saurischian dinosaur from the Dinosaur National Monument, Utah. Memoirs of the Carnegie Museum 10: 347-384
Read the paper : A nearly complete articulated skeleton of Camarasaurus, a saurischian dinosaur from the Dinosaur National Monument, Utah (opens in a new tab)Its world
Chemical signatures in teeth suggested that Camarasaurus drank upland water and may have migrated between uplands and lowland floodplains.
Lowland–upland migration of sauropod dinosaurs during the Late Jurassic epoch. Nature 480: 513-515
Read the paper : Lowland–upland migration of sauropod dinosaurs during the Late Jurassic epoch (opens in a new tab)Skull
Described a nearly complete skull and found variation in skull proportions across Camarasaurus specimens.
A new specimen of the basal macronarian Camarasaurus (Dinosauria: Sauropoda) highlights variability and cranial allometry within the genus. Volumina Jurassica 19: 109-130
Read the paper : A new specimen of the basal macronarian Camarasaurus (Dinosauria: Sauropoda) highlights variability and cranial allometry within the genus (opens in a new tab)
Close relatives
Other members of Camarasauridae
Sources: Wikidata