The American Museum J 



OURNAL 



Volume XVII 



JANUARY. iU17 



Number 1 



The "Ostrich" Dinosaur and the 

 "Tyrant" Dinosaur 



By H E X R Y FAIRFIELD O S B O R X 



This article illustrates some of the methods as well as the "perils" of the restoration of 

 extinct animals from their more or less complete skeletons. A restoration presents the 

 author's theory of the habits of the animal, how it moved, how it fed, how it attacked its 

 prey or escaped from enemies, also the environment in which it lived. In the present in- 

 stance a dinosaur which was restored and named by the author as an habitual "bird robber" 

 has proved through our discovery of one of its descendants to have followed a less destruc- 

 tive calling. This descendant is known as the "ostrich dinosaur," in relation to a theory of 

 its habits which may in turn prove untenable.^ — The Author. 



OXE of the American Museum 

 expeditions of 1902 was hunt- 

 ing dinosaurs in the great geo- 

 logical deposit known as the "Bone- 

 Cabin Quarry" in central Wyoming, not 



far north of the old line of the Union 

 Pacific Railway. Among the remains 

 of hundreds of skeletons of large forms 

 which we found crowded into this 

 quarry, we discovered one very small, 



Ornitholestes, the "Bird Robber," and Archaopterj/x. ~Originn\ restoration, b.v Osborn and Knight, 

 of Ornitholestes as a bird robber, capturing an Archceopteryx. Now regarded as an improbable inter- 

 pretation of the habits of this animal 



