Camarasaurus, the chambered sauropod from Morrison rock

When and where

Camarasaurus lived about 155 to 145 million years ago, near the end of the Jurassic Period. Its fossils come from the Morrison Formation of North America, a rock unit famous for sauropods and big meat-eating dinosaurs. The landscape was not one single habitat. Rivers, floodplains, and drier stretches all left their mark in the rocks where Camarasaurus bones later turned up.

How we know

Edward Drinker Cope named Camarasaurus in 1877, during the rush of American dinosaur discoveries that made the Morrison Formation famous. The name means "chambered lizard" and points to the hollow spaces, called pleurocoels, inside its cervical vertebrae. Hundreds of specimens have been found, including some nearly complete skeletons, so this is not a dinosaur known from one scrap of bone. Researchers recognise three main species: C. supremus, C. grandis, and C. lentus. Source: Wikipedia.

What set it apart

Camarasaurus was a sauropod, but it did not have the extreme pencil-like neck of Diplodocus. Its skull was shorter and deeper, with strong spoon-shaped teeth suited to cropping plant material. Those hollow neck bones mattered because they cut weight without making the neck uselessly weak. That is a practical detail, not a trivia point: a large sauropod had to carry a long neck all day while feeding. Camarasaurus also matters because the fossil record is unusually generous. With so many bones, palaeontologists can compare growth stages, species differences, and body proportions instead of building the whole animal from a single partial skeleton.

For collectors and classrooms

A Camarasaurus model is useful beside Diplodocus or Brachiosaurus because the differences are easy to see: deeper skull, sturdier neck, and a more compact sauropod outline. It gives a class a clean way to ask why not all long-necked dinosaurs were shaped the same. If you are building a Morrison Formation shelf or lesson box, start with the reserved pick here: Camarasaurus figurine.