Cretaceous Dinosaurs 
9 
Available femora of Albertosaurus libratus (Lambe) from the Oldman 
Formation (AMNH 5458 and 5664) are either too crushed or too inac- 
cessible (being embedded in panel-mounted skeletons) to be useful for 
comparison. A right femur of Albertosaurus sarcophagus Osborn from the 
lower Edmonton Formation (AMNH 5218) is closely comparable in both 
proportions and morphological detail to -the Phoebus Landing femur and 
that of Dryptosaurus. The right femur of Daspletosaurus torosus Russell 
(AMNH 5438, paratype) from the Oldman Formation is essentially 
similar to all the foregoing, differing mainly in that, on the ventral sur- 
face, the ridge that runs proximally from the inner condyle crosses the 
shaft at an angle of 32° to the femoral axis, as compared to 20° in the 
Phoebus Landing femur and 23° in Dryptosaurus and Albertosaurus (angles 
approximate). The lower shaft of the Daspletosaurus femur also appears 
broader in proportion to its depth, although crushing makes this factor 
uncertain. 
The right femur of Alectrosaurus olsem Gilmore (AMNH 6554, syntype) 
from the Iren Dabasu Formation of Mongolia differs conspicuously from 
all the foregoing in morphology as well as in its slenderer proportions. On 
the ventral surface it lacks strong ridges extending anteriorly from the 
condyles, while on the dorsal surface the scar for the origin of the 
femorotibialis muscle is much less sharply demarcated both proximally 
and distally, with the result that no pronounced break in slope is evident 
in lateral view. 
In conclusion, so far as its preservation permits comparison 
Dryptosaurus is not distinguishable from Albertosaurus on the basis of the 
distal end of the femur. The femur from Phoebus Landing is extremely 
similar to both, differing in that its diaphysis is slightly deeper relative to 
width, so that the lumen is circular rather than oblate in section. It is less 
similar to Daspletosaurus and quite different from Alectrosaurus. Having 
made these comparisons, we do not feel that the material available per- 
mits a generic identification for the North Carolina tyrannosaurid. 
Infraorder COELUROSAURIA 
Family ORNITHOMIMIDAE 
cf. Ormthomimus Marsh, 1890 
A single toe bone of an ostrich-mimic dinosaur from Phoebus Landing 
(ANSP 15319) was described by Miller (1967: 232, PI. 3, Fig. 7) who 
compared it to the first phalanx of the third digit of Ormthomimus altus 
Lambe. This specimen is water-worn, with abraded proximal and distal 
ends. The bone is symmetrical when viewed from either end. At its prox- 
imal end the ventral surface is smooth and flat while the upper profile 
