Neither bone was in the best of condition and, in consequence, a small allowance may be necessary in the figures given below: those for the left bone are the more reliable.
COMPARATIVE MEASUREMENTS OF RADIUS
Parasaurolophus |
Kritosaurus |
Saurolophus | ||
|---|---|---|---|---|
| right | left | |||
| Length | 485 | 496 | 555 | 620 |
| Girth of shaft, one-third from distal end | 152 | 152 | – | |
| Girth at middle | 160 | 148 | 136 | |
| Girth, one-third from prox. end | 140 | 146 | ||
Carpals—In both limbs a small carpal was found lying on the distal posterior edge of the ulna: a second carpal was not observed.
Manus (Plate VIII. Fig. 3; Plate IX, Figs. 1, 2, 3, and 4)–As in the case of the other elements of the fore limb the manus is short. Metacarpals III and IV are closely associated and longest; metacarpal II is somewhat shorter, but nevertheless closely associated with III and IV. Metacarpal V is much smaller and divergent. The phalangeal formula of trachodonts was discussed in a former paper.[1] Although the terminal phalanx of Digit V is lacking, there seems no reason to doubt that the formula for Parasaurolophus is the same as that for Kritosaurus as follows:
Digit II with three phalanges, the third a pointed hoof.
Digit III with three phalanges, the third a broader hoof.
Digit IV with three phalanges, no hoof.
Digit V with four phalanges, the terminal a small ovoid bone (this last phalanx is not preserved).
As in the case of Kritosaurus, phalanges II2 and III2 are triangular with the thin edge directed inwards: in the case of the latter of these bones, the triangular character is not so marked as in Kritosaurus.
- ↑ Parks, University of Toronto Studies, Geol. Ser., No. 11, 1920.
