The chambered lizard: how a common dinosaur shaped our view of the giants

Nature · Published 3 October 2026 Swipe more like this →

In short: Camarasaurus is the most common sauropod in North America's Morrison Formation, yet its legacy is defined by a case of mistaken identity. For decades, its distinctive, robust skull was mistakenly used to complete the skeletons of other famous dinosaurs, fundamentally altering how the public perceived these prehistoric titans.

Named in 1877 by Edward Drinker Cope, Camarasaurus—meaning 'chambered lizard'—derives its name from the air-filled cavities within its vertebrae. These structures, connected to the lungs, allowed for a lighter frame despite the animal's bulky, elephant-like appearance. Living during the Late Jurassic, this sauropod was a selective feeder, using its powerful, spoon-shaped teeth to browse at heights between 2 and 5 meters. With over 530 specimens recovered, it remains one of the best-understood sauropods in the fossil record.

The genus was a central player in the 'Bone Wars,' a fierce 19th-century rivalry between paleontologists Cope and Othniel Charles Marsh. While Cope described Camarasaurus from Colorado, Marsh named a similar genus, Morosaurus, from Wyoming. These were eventually synonymized, as were other genera like Uintasaurus and Cathetosaurus. The confusion extended to museum displays: because the original Apatosaurus and Brontosaurus mounts lacked skulls, curators frequently topped them with casts of Camarasaurus heads. It was not until 1975 that the true, diplodocid-like skull of Apatosaurus was identified, finally correcting these long-standing anatomical errors.

Camarasaurus specimens provide rare insights into dinosaur biology, including skin impressions, evidence of arthritis, and bite marks. One juvenile specimen, CM 11338, is considered among the most complete sauropod skeletons ever found. While the most common species, C. lentus, reached about 15 meters in length, the larger C. supremus may have grown significantly longer. Today, Camarasaurus is classified as a basal member of the Macronaria group, serving as a vital reference point for understanding the evolution and diversity of the largest land animals in history.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• The Knob Lizard: How a Cretaceous Apex Predator Became a Subject of Scientific Rivalry
• The thunder lizard was never a fake, but its identity was a scientific casualty.
• The thunder lizard that vanished and returned: why Brontosaurus is finally back
• The Horned Lizard of the Jurassic: Unmasking the Ceratosaurus
• The Thick-Nosed Lizard: Why This Hornless Giant Roamed the Cretaceous North
• Why a failed agricultural experiment created one of the world's most successful invasive pests.
• The elephantfish is an ancient, electro-sensing survivor with a genome smaller than ours
• From the Sahara to the Arctic, the canine family has conquered almost every ecosystem.
• Once extinct in the wild, the California condor is a survivor of the Ice Age
• Beyond the Goldfish Bowl: The Surprising Diversity of the Carassius Genus
• The rabbit-like ungulates of ancient Europe were not the leapers we once imagined
• The hidden viral diversity lurking within shelter dog populations

More in Vertebrates · More in Nature · Latest · A–Z · All topics