Camarasaurus

Camarasaurus, whose name means "chambered lizard" due to the pneumatic hollows in its vertebrae, is the most frequently collected and thoroughly studied sauropod from the Morrison Formation. Edward Drinker Cope described the genus in 1877 during the "Bone Wars" with Othniel Charles Marsh. Despite the taxonomic confusion of that period, Camarasaurus has remained a stable and well-recognised genus.

This robust, mid-sized to large macronarian sauropod is known for its deep, short skull, which appears boxy or horse-like in profile. It featured large nasal openings high on the head and large, spoon-shaped (spatulate) teeth in both jaws. These teeth suggest the animal occupied a different dietary niche than peg-toothed diplodocids, likely focusing on tougher vegetation. The dinosaur had a relatively short neck for a sauropod, with 12 cervical vertebrae. Its back was straight, its tail was of medium length, and its limbs were robust and columnar, with the forelimbs slightly shorter than the hindlimbs.

Paleontologists recognise three or four species: C. supremus (the largest and type species), C. grandis, C. lentus, and occasionally C. lewisi, though the latter is sometimes assigned to the genus Cathetosaurus.

Camarasaurus coexisted with other Morrison giants like Diplodocus, Apatosaurus, and Brachiosaurus. Its spatulate teeth and deep skull suggest it was a mid-level browser that consumed tough conifer needles and woody plants. Because hundreds of specimens have been found, including complete growth series, researchers understand Camarasaurus better at every life stage than almost any other sauropod.

A 2014 study by Strickson et al. analyzed neural features and the foramen magnum, finding that Camarasaurus possessed a respiratory system similar to that of modern birds. This supports the broader consensus that sauropods utilised a system of air sacs and pneumatised bones for breathing.

• CM 11338 — Carnegie Museum C. lentus juvenile; nearly complete and articulated.
• AMNH 5761 — C. supremus type material, American Museum of Natural History.
• Howe Quarry assemblage — multi-individual Morrison locality, multiple institutions.
• Sauriermuseum Aathal Camarasaurus — Switzerland, well-preserved specimens.

Cathetosaurus validity — C. lewisi has been argued to deserve its own genus. Species count — most workers accept 3–4 species. Diet vs other Morrison sauropods — the niche partitioning model (peg-tooth diplodocids low-browse, spoon-tooth camarasaurs and brachiosaurs high-browse) is widely supported but debate continues over precise dietary overlap.

Camarasaurus skulls were historically (mis)matched onto diplodocid skeletons in early museum mounts, leading to decades of incorrect Apatosaurus and Brontosaurus head reconstructions. Camarasaurus itself is less famous than Apatosaurus in popular culture but is the most abundantly represented sauropod in Morrison-era museum collections.

• sauropodomorpha
• diplodocus
• apatosaurus
• brachiosaurus
• allosaurus

• McIntosh, J. S. (1990). Sauropoda. In The Dinosauria (1st ed.).
• Foster, J. (2007). Jurassic West: The Dinosaurs of the Morrison Formation. Indiana University Press.
• Wedel, M. J. (2003). Vertebral pneumaticity, air sacs, and the physiology of sauropod dinosaurs. Paleobiology, 29, 243–255.
• Carpenter, K., & McIntosh, J. S. (1994). Upper Jurassic sauropod babies from the Morrison Formation. In Carpenter, Hirsch & Horner (eds.) Dinosaur Eggs and Babies.