86 
position of tracks. 
It is more than forty years since the rich dinosaur 
fields were discovered along Red Deer river in Alberta 
and during that time many fine specimens have been 
collected, which show that in late Cretaceous time this 
country teemed with dinosaurs and other animals. In 
the Edmonton formation there is evidence that there 
were large, brackish-water pools and marsh-lands, and 
large tidal flats at the time these rocks were being laid 
down. Ripple-marked sandstones are common, especi- 
ally in the upper part of the formation. In spite of 
these conditions, which one would think favourable 
for the preservation of dinosaur tracks, no such speci- 
mens have as yet been recorded from these rocks. 
During the field season of 1925 the Geological 
Survey field party, under the direction of the writer, 
collected four dinosaur tracks from the Edmonton for- 
mation along Red Deer river, southwest of Rumsey, 
Alberta. They were discovered in the NE. £ sec. 6, 
tp. 33, range 21, W. 4th mer., 110 feet above river level. 
The tracks were made in a stiff mud and the impres- 
sions were rather shallow but clean cut. This mud 
was then covered with a medium-grained sand which 
filled the impressions made by the feet of the dinosaur. 
This has since become solidified, in certain areas, due 
to the concentration of calcareous cement. The speci- 
mens are, therefore, the negative or mould of the track 
and were on the under side of the solidified ledge. As 
only these solidified areas were of such a nature as to 
preserve the impressions, it was not possible to follow 
the path of the animal beyond these areas. 
Two of the tracks were side by side and may 
have been made by an animal standing with its feet 
very close together, but more probably were made at 
different times. The better one of these is of the 
right foot and though it is not deep it is clean cut and 
shows good detail (Plate XVIII). The other is so faint 
that it is not possible to state whether it is of the right 
or left foot. The other two tracks are in almost a 
straight line and appear to have been made by an 
animal walking, rather than running, with the weight 
thrown strongly to the outside. The stride was 3 feet 
1 inch, as shown by measuring from the tip of the 
third or central toe of one foot to the same point on 
the other. 
The form, relative position, and the absence of 
manus impressions show clearly that the tracks are 
those of a bipedal, tridactyl, digitigrade animal. 
Phalangeal pads are moderately well shown, but there 
are no distinct metatarsal pads and there is no 
evidence of a web covering the toes. The heel is short 
and the toes well spread. The so-called heel is* 
