18 
in the total number of presacrals. The information already available is 
sufficient to indicate that regardless of distinctive features to be found in 
the vertebrae themselves, the vertebral formulae as a whole will furnish 
important diagnostic characters in the Hadrosauridae. The present 
specimen in this respect is, therefore, of the greatest scientific interest, as 
being one of the very few skeletons known in which the presacral series is 
completely preserved. 
Known Vertebral Formulee of the Hadrosauridae 
Name 
Museum and 
catalogue 
number 
Cervicals 
Dorsals 
Sacrals 
Caudals 
Total 
number 
of pre- 
sacrals 
Thespesius edmontoni n. sp.... 
G. S. C. 
12 
20 
9 
5+ 
32 
8799 
Thespesius anneciens (Marsh) 
U.S.N.M. 
2414 
11? 
19? 
9 
62+ 
30? 
tt it 
Y.M. 
2182 
11? 
19? 
9 
23+ 
30? 
Diclonius mirabilis Cope 
A.M.N.H. 
5730 
16 
18? 
9 
34? 
Cl II 
A.M.N.H. 
5894 
16? 
18 
9 
34? 
Kritosaurus incurvimanus 
Univ. of 
Parks 
Toronto 
13 
16 
9 
17+ 
29 
Edmontosaurus regalis Lambe 
G.S.C. 
9 l 
2289 
Corythosaurus casuarius Brown 
A.M.N.H. 
5240 
15 
19 
8 
61 + 
34 
Saurolophus osborni Brown.. 
A.M.N.H. 
5220 
12? 
20? 
8 
50+ 
32? 
Hypacrosaurus altispinus 
A.M.N.H. 
Brown 
5204 
8 
Parasaurolophus walkeri Parks 
Univ. of 
13 
17 
7 
6+ 
30 
T oronto 
In order to render the vertebral formulae of these animals of the 
greatest diagnostic utility a uniform method of determining the point of 
division between the cervical and dorsal regions should be adopted. At 
present, it is necessary to select a division point arbitrarily, for in the 
transitional vertebrae one cannot certainly determine whether they properly 
belong to the cervical or to the dorsal series. It is, therefore, proposed to 
regard as cervical all those vertebrae bearing short slender ribs. In other 
words, none of the cervical ribs with the scapula in position are of sufficient 
length to pass well down behind it or to protrude below its ventral border. 
This procedure would render the formulae in some forms somewhat different 
than originally determined, but it would bring about a greater uniformity. 
In Thespesius anneciens (Marsh), “There are thirty 2 vertebrae between 
the skull and sacrum, nine in the sacrum, and about sixty in the tail. The 
whole vertebral column was found in position except the terminal caudals”. 
lAs shown by the paratype there are nine sacral vertebrae instead of eight as originally given 
by Lam be, Geol. Surv., Can,, Mem. 120, 1920, p. 66. 
a Dinosaurs of North America”, U.S. Geol. Surv., 16th Ann. Rept., 1896, p. 222. 
