73 
A NEW SPECIES OF THESPESIUS FROM THE LANCE 
FORMATION OF SASKATCHEWAN 
By C. M. Sternberg 
CONTENTS 
Page 
Introduction 73 
Discussion of Thespesius and other related genera 73 
Description of species 75 
Illustrations 
Plates XV to XVII. Illustrations of fossils 129-133 
Figure 3. Enamel face of dentary teeth 81 
INTRODUCTION 
During the season of 1921 the writer made a collection of dinosaurian 
and other vertebrate remains from the bad lands on the southern face of 
Wood Mountain plateau, southern Saskatchewan. The beds from which 
these remains were collected have been referred to the Lance formation 
largely on the evidence of their vertebrate fossils. 1 
The most important specimen in this collection represents an 
undescribed species of a hadrosaurian dinosaur. Although dinosaurian 
remains were reported from these beds, by Dr. G. M. Dawson, as early 
as 1875, this is the first specimen found in Saskatchewan of which a consider- 
able part of the skeleton is preserved. It was discovered by the writer 
on a tributary of Rocky creek in section 22, township 1, range 5, west of 
the third principal meridian, in an argillaceous sand 55 feet below the 
lowermost coal seam, which is about the middle of the Lance formation 
as here exposed. 
The writer is greatly indebted to Mr. C. W. Gilmore, Curator of 
Vertebrate Palaeontology in the United States National Museum, Washing- 
ton, D.C., for very helpful criticism of this paper. 
DISCUSSION OF THESPESIUS AND OTHER RELATED 
GENERA (OF THE HADROSAURIDAE) 
The genus and species Trackodon mirabilis , 2 founded on teeth and tooth 
fragments from the Judith River formation of Montana, was the first 
member of the Hadrosauridae to be described. Since that time the generic 
name Trachodon has been used by different writers for the reception of all 
^Sternberg, C. M.: “Notes on the Lance Formation of Southern Saskatchewan"; Can. Field Nat., vol. 
XXX VUI, pp. 66-70 (April, 1924). 
* Proc. Acad. Nat. Sci., Phila., vol. VIII, p. 72 (1866). 
