5 
The elements of the skull of the paratype, and the few vertebrae and 
bones of the fore limb mentioned in this report, were prepared by G. F. 
Sternberg who had charge of the 1916 expedition. It is hoped soon to 
assemble the elements of this skull and to so mount them that as many 
as possible will be removable for study purposes. 
As the greater part of the skeleton is present in the above specimens 
an open mount of both is contemplated. 
OSTEOLOGY OF EDMONTOSAURUS. 
SKULL. 
The skull of Edmontosaurus is large, massive, and long, high behind 
and low in front. Posteriorly it is higher than broad, anteriorly it is 
greatly expanded horizontally outward into a beak-like termination. 
Viewed from the side its outline is subtriangular, high behind, approxi- 
mately straight horizontally below, flat above behind the orbits, with a 
long facial slope descending rapidly forward. 
As seen from above the skull is broadest in its posterior half-length, 
much expanded in front, and greatly constricted behind this expansion. 
The outline of the occiput is squarely transverse, and the margin of the 
snout has a semicircular curve. Behind the concavity of the anterior 
constriction the lateral outline is broadly convex backward. 
The posterior height of the skull is greater than half its length. The 
maximum breadth behind exceeds the full lateral expansion of the beak, 
but is considerably less than the half-length. The orbit is large, as is 
also the narial opening. The supratemporal fossae are of fair size, but 
the lateral temporal ones though high are greatly reduced in width. 
Concomitant with the posterior height of the skull is a long quadrate. 
The great development of the flattened snout is remarkable, and the depth 
and robustness of the mandible are equally striking. 
Elements of the Skull Known in Edmontosaurus, 
Alisphenoid 
Als. 
Parasphenoid 
Pasp. 
Angular 
An. 
Parietal 
P. 
Articular (in part) 
Ar. 
Postfrontal 
Pof. 
Basi-occipital 
Boc. 
Predentary 
Pd. 
Basisphenoid 
Bs. 
Prefrontal 
Prf. 
Dentary 
Dn. 
Premaxillary 
Pmx. 
Ectopterygoid (Trans- 
palatine) 
Exoccipital 
Ept. 
Presphenoid 
Psp. 
Exo. 
Prootic 
Prot. 
Frontal 
F. 
Pterygoid 
Pt. 
Jugal 
J. 
Quadrate 
Q. 
LachrjTnal 
L. 
Quadrato-jugal 
Qi- 
Maxillary 
Mx. 
Splenial 
Sp. 
Nasal 
N. 
Squamosal 
Sq. 
Opisthotic 
Opot. 
Supra-occipital 
Soc. 
Orbitosphenoid 
Orsp. 
Surangular 
Sa. 
Palatine 
Pal. 
Vomer (in part) 
V. 
