THE OTTAWA NATURAL 



Vol. XXVII. February, 1914 No. 1 1 



ON GRYPOSAURUS XOTABILIS, A NEW GENUS AND 

 SPECIES OF TRACHODONT DINOSAUR FROM THE 

 BELLY RIVER FORMATION OF ALBERTA, WITH A 

 DESCRIPTION OF THE SKULL OF CHASMO- 

 SAURUS BELLI.* 



By Lawrence M. Lambe, F.G.S., F.R.S.C, F.G.S.A., 

 Wrtebrate Palaeontologist to the Geological Survey, Canada. 



In two papers lately published the writer has described 

 some of the dinosaurian material included in the 1913 collection, 

 made by the Geological Survey's vertebrate palaeontological 

 party in the Belly River formation on Red Deer river. Alberta, 

 under Mr. Charles H. Sternberg. 



The present paper is descriptive of a skull representing a 

 new genus and species of trachodont, and of that of Chasmosaurus 

 belli, both forming part of last summer's collection. 



The skull of the trachodont is remarkable for its splendid 

 state of preservation. The elements composing it are singularly 

 free from breaks and displacement, there is little or no distor- 

 tion, and the specimen is as close an approach to perfection as 

 can be expected in a fossil vertebrate of large size. 



With the skull were found about twenty feet of the verte- 

 bral column, most of the pectoral arch, about half of the ribs, 

 the pelvic arch, one hind limb with part of the foot, and impres- 

 sions of the skin from between the femur and the base of the tail. 

 The discoverer of these remains was George F. Sternberg, who 

 has also prepared the skull as shown in side view, on plate 

 XVIII. 



For the genus and species represented the name Grypo- 

 saurus notabilis is proposed, the generic term having reference 

 to one of the most striking features of the skull, viz., the pro- 

 minence attained by the upper marginal curve of the nasal 

 bones. 



The genus mav be denned as follows: Skull large, narrow 

 and very deep, with highly arched nasals. The lower anterior 

 border of the premaxillae expanded laterally. Orbit much 

 smaller than the lateral temporal fossa. Quadrate high, partially 



Communicated by permission of the Director of the Geological Survey. 



