Ceratosaurus

MEET THE ANIMAL

Meet Ceratosaurus

Ceratosaurus was a meat-eating dinosaur of the Late Jurassic Morrison Formation. A horn formed from the nasal bones adorned the top of its snout. At Dinosaur National Monument, a single front upper-jaw bone identifies its presence: that bone holds three teeth, a useful difference from other local predatory dinosaurs. Ceratosaurus is considerably rarer in these fossil assemblages than Allosaurus. [D2]

The Smithsonian preserves the skeleton used to name and describe Ceratosaurus. Such an important reference is called a type specimen; later discoveries can be compared with it. Its long, blade-like teeth and row of bony armor along the back add to the distinctive outline. For many years, however, part of this skeleton remained hidden inside rock and a museum wall, limiting the areas scientists could examine. [S1]

Preparing that fossil again exposed parts that had not been accessible for close study. It also allowed casts to be made for a dramatic exhibit beside Stegosaurus. A museum battle scene helps visitors imagine these animals, but it is a reconstruction, not a preserved record of that particular fight. The fossil gives stronger evidence for anatomy and identification than for a complete hunting routine, courtship or parental care. [S1]