Page:Parasaurolophus walkeri, a new genus and species of trachodont dinosaur.pdf/32

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Pelvic Girdle

prepubis. A peculiar feature is that the ilium seems to form an overlapping union with the pubis instead of abutting against it as in other forms. After a careful examination, I am of the opinion that this arrangement is not due to deformation.

Ilium (Fig. 8, Plate VI)–This bone is very massive with stout ischiac peduncle above which the overhanging shelf is sharply defined and comes low down. The pubic peduncle

Figure 8. Left pelvic girdle, external view. One-twelfth natural size.

is unusually extended anteriorly, decurved at its anterior end and fastened to the pubis by an externally overlapping joint. Even if this manner of union is due to distortion, there can be no doubt as to the quite unique character of the anteriorly extended pubic peduncle.

Ischium (Fig. 8, Plate VI)–This bone seems to be less massive than the ilium and to present nothing of particular interest. Only the proximal portion is preserved, but the distal end has been restored with a "foot" in the mount.

Pubis (Fig. 8, Plate VI)–The prepubis is generally like that of Saurolophus, but has an outline sufficiently different to distinguish it. The anterior end is much less decurved and the narrow portion is relatively wider. It differs greatly