THE SKULL STRUCTURE OF DIPLOCAULUS MAG- 



NICORNIS COPE AND THE AMPHIBLIN 



ORDER DIPLOCAULIA 



ROY L. MOOD IE 



From the Zoological Laboratory, the University of Kansas 



SEVEN FIGURES 



The Permian vertebrate known as Diplocaulus magnicornis 

 Cope is one of the most aberrant and speciahzed of all the extinct 

 Amphibia. The species was first described by Cope from frag- 

 ments of several crania and portions of the vertebral colmnn; 

 material which had been collected in the Permian of Texas prior 

 to 1882. The genus had, however, been established previously 

 on fragmentary material which had been discovered by Dr. J. C. 

 Winslow and Mr. W. F. E. Gurley in the Pennsylvanian of Ver- 

 milion County, Illinois. The genus Diplocaulus was first located 

 by Cope in 1881 among the Pelycosauria, but later researches 

 inclined him to place the form among the stegocephalous Am- 

 phibia with relationships to the Microsauria. 



The skull of Diplocaulus magnicornis is very peculiar in the 

 elongation of the posterior elements of the upper surface of the 

 cranium. The anterior elements do not take part in the posterior 

 prolongations which give the skull such a bizarre appearance. 

 This specialization is due to the extreme elongation of the supra- 

 temporal, the squamosal, the parietal, the epiotic and the supra- 

 occipital. 



The pineal foramen is apparently absent. I was unable to dis- 

 cover it on a well preserved skull in the collection of the Univer- 

 sity of Chicago (No. 2, U. of C. Collections). Cope figured it 

 on the skull of this species which he studied in 1895. Broili 

 says nothing of the presence of the opening and does not figure 

 it in the restoration of the skull which he gave in 1902. Williston 



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