Age: Late Jurassic (~150 million years ago)
Where It's Found in Utah: Many localities throughout the Colorado Plateau region of central, eastern, and southern Utah, including Cleveland-Lloyd Dinosaur Quarry, Emery County, and Dinosaur National Monument, Uintah County.
Geologic Formation: Morrison Formation (Salt Wash and Brushy Basin members)
Classification: Saurischia - Sauropodomorpha – Sauropoda – Macronaria
Description: Although Camarasaurus is considered a “smaller” sauropod dinosaur, it was still between 50-65 feet (15-20 meters) long, 15-25 feet (4.5-7.5 meters) tall, and may have weighed up to 20 tons (18,143 kilograms)! It had a small, square-shaped head and short round snout. Its unusually large chisel- or spoon-shaped teeth equipped Camarasaurs to browse on a wide variety of vegetation. Its front legs were slightly shorter than its hind legs and its neck and tail were proportionally shorter than most sauropods.
Why It’s a Top NHMU Dinosaur: Along with Allosaurus, Camarasaurus is the most common dinosaur found in the Late Jurassic of Utah and all of North America. This sauropod was also likely an occasional meal for Allosaurus. A Camarasaurus pelvis recovered from Utah’s Dinosaur National Monument shows gouging attributed to Allosaurus teeth! Camarasaurus derives its name, meaning “chambered lizard,” from the hollow air-sacs in its neck vertebrae. Paleontologists believe these air-sacs helped make the bones in its very long neck both light and strong, like the air-sacs in the bones of living birds. Camarasaurus and other sauropods swallowed stones that remained in their stomachs. Paleontologists used to think these stones helped sauropods break down plant matter, but new studies suggest they may have provided nutrients, like calcium, from various minerals.
Foster, J. 2007. Jurassic West: The Dinosaurs of the Morrison Formation and their World. Indiana University Press, Bloomington, 389 pp.
Gilmore, C. W. 1925. A nearly complete articulated skeleton of Camarasaurus, a saurischian dinosaur from the Dinosaur National Monument, Utah. Memoirs of the Carnegie Museum 10:347-384.
Madsen, J. H., Jr., J. S. McIntosh, and D. S. Berman. 1995. Skull and atlas-axis complex of the Upper Jurassic sauropod Camarasaurus Cope (Reptilia: Saurischia). Bulletin of Carnegie Museum of Natural History 31:1-115.
McIntosh, J. S., C. A. Miles, K. C. Cloward, and J. R. Parker. 1996. A new nearly complete skeleton of Camarasaurus. Bulletin of the Gunma Museum of Natural History 1:1-87.
McIntosh, J. S., W. E. Miller, K. L. Stadtman, and D. D. Gillette. 1996. The osteology of Camarasaurus lewisi (Jensen, 1988). Brigham Young University Geology Studies 41:73-115.
Image: © Victor Leshyk
Author: Deanna Brandau, Paleontology Graduate Student at the Natural History Museum of Utah (2012)