RESTORATION OF EDAPHOSAURUS CRUCIGER 

 COPE 



Professor E. C. CASE 

 University op Michigan 



In the year 1882 Cope described from the Permian beds 

 of Texas, an imperfect reptilian sknll which he called 

 Edaphosaurus pogonias. Two years later he described 

 for the first time, the wonderful vertebrae with elongate 

 spines bearing lateral projections on the sides. These 

 vertebra? he assigned to the same genus as the skull but 

 later they were removed to a separate genus as he con- 

 sidered that the two specimens represented different 

 forms of reptilian life. The vertebras with long spines 

 and cross pieces were placed in the genu3 Naosaurus— 

 " Ship-lizard,' ' a name suggested by the fancied resem- 

 blance of the spines with their lateral projections to the 

 masts and yard-arms of a full-rigged ship. 



From the time of the original description until 1907 the 

 two genera were regarded as distinct but in that year 

 Case 1 suggested that the two genera should be united and 

 that the skull described as Edaphosaurus by Cope be- 

 longed with the vertebral column and limb bones de- 

 scribed under the name Naosaurus. The similar condi- 

 tion of elongate spines, but without cross pieces, on the 

 vertebrae of the carnivorous genus Dimetrodon very nat- 

 urally led to the belief that the two forms Edaphosaurus 

 and Dimetrodon were similar in other parts of the body 

 and Naosaurus merely exhibited something of the extrav- 

 agance in spines, rugosities, tubercles, etc., which is such 

 a common feature in the most highly specialized members 

 of any group which is approaching the final stages of its 

 family or generic life. The close relationship of the two 

 genera was so probable that it was accepted by all paleon- 



1 Publication 55, Carnegie Institution of Washington. 



117 



