4G 
Measurements No. 2869 N0.351 
Mm. Mm. 
Greatest transverse width of predentary 158 190 
“ length antero-posteriorly 160 170 
“ length at centre, lacking median process 52 62 
Teeth 
The teeth in both the dentary and maxillary series are arranged in 
vertical and horizontal series as in all the known Hadrosauridae. Both 
upper and lower teeth are largest in the middle of the dental magazines 
and decrease in size toward either end, but more especially at the anterior 
extremity. The lower anterior teeth of the dentary also have the most 
pronounced papillation of the entire series, and are especially reduced in 
width. This feature is not so pronounced apparently in the maxillary 
series. The nonfunctional teeth in the dentary may be described as 
A B 
Figure 12. Enamelled face of dentary teeth of Lambeusaurus lambci Parks. No. 351, Geol. 
Surv., Can. A, taken from the twentieth to twenty-second vertical series from the front of the 
right dentary; B, taken from the first to fifth vertical series from the front of same. Natural size. 
lozenge-shaped, rather acutely rounded above and apparently pointed 
below. There is no evidence of the lower ends being emarginated as 
Lambe has found them in Edmontosaurus. The upper tip of the next 
lower tooth in the series overlaps the base of the one above, shinglewise, 
and nowhere do I find evidence of a notch. All the teeth have high, broad- 
based, sharp-edged, median keels that traverse the greater pairt of their 
length, subsiding, however, before reaching the lower end and thus producing 
a smooth surface for the overlap of the succeeding tooth. There is a slight 
elevation of the margins, especially on the upper half of the anterior side. 
The enamelled surfaces of the dentary teeth do not lie flat in relation to 
the longer axis of the jaw, but are slightly oblique with the edge toward 
the front, standing out more prominently than the posterior border. A 
majority of the teeth, especially of the posterior half, have smooth margins, 
becoming progressively more and more papillate toward the front of the 
