 The popularity of Stegosaurus is owed partly to its prominent display in natural history museums . Though considered one of the most distinctive types of dinosaur , Stegosaurus displays were missing from a majority of museums during the first half of the 20th century , due largely to the disarticulated nature of most fossil specimens . Until 1918 , the only mounted skeleton of Stegosaurus in the world was O.C. Marsh 's type specimen of S. ungulatus at the Peabody Museum of Natural History , which was put on display in 1910 . However , this mount was dismantled in 1917 when the old Peabody Museum building was demolished . This historically significant specimen was re @-@ mounted ahead of the opening of the new Peabody Museum building in 1925 . 1918 saw the completion of the second Stegosaurus mount , and the first depicting S. stenops . This mount was created under the direction of Charles Gilmore at the U.S. National Museum of Natural History . It was a composite of several skeletons , primarily USNM <unk> , with proportions designed to closely follow the S. stenops type specimen , which had been on display in relief nearby since 1918 . The aging mount was dismantled in 2003 and replaced with a cast in an updated pose in 2004 . A third mounted skeleton of Stegosaurus , referred to S. stenops , was put on display at the American Museum of Natural History in 1932 . Mounted under the direction of Charles J. Long , the American Museum mount was a composite consisting of partial remains filled in with replicas based on other specimens . In his article about the new mount for the museum 's journal , Barnum Brown described ( and disputed ) the popular misconception that the Stegosaurus had a " second brain " in its hips . Another composite mount , using specimens referred to S. ungulatus collected from Dinosaur National Monument between 1920 and 1922 , was put on display at the Carnegie Museum of Natural History in 1940 . 
