he top of the
skull; in _Corythosaurus_ there is a thin high crest like the crown of
a cassowary on top of the skull, and the muzzle is short and small
giving a very peculiar aspect to the head. Complete skeletons of these
two genera are exhibited in the Dinosaur Hall; the _Corythosaurus_ is
worthy of careful study, as the skin of the body, hind limbs and tail,
the ossified tendons, and even the impressions of the muscular tissues
in parts of the body and tail, are more or less clearly indicated.

[Illustration: Fig. 34.--SKELETON OF SAUROLOPHUS, FROM UPPER
CRETACIC OF ALBERTA. _After Brown_]

These Duck-billed Dinosaurs probably ranged all over North America and
the northerly portions of the Old World during the later Cretacic.
Fragmentary remains have been found in New Jersey and southward along
the Atlantic coast. A partial skeleton was described many years ago by
Leidy under the name of _Hadrosaurus_ and restored and mounted in the
museum of the Philadelphia Academy of Sciences. _Telmatosaurus_ of the
Gosau formation in Austria also belongs to this group, and fragmentary
remains have been found in the upper Cretacic of Belgium, England and
France.

FOOTNOTES:

[Footnote 16: Brown, Barnum. "The Trachodon Group." Amer. Mus. Jour.
Vol. viii, pp. 51-56, plate and 3 text figs., 1908.]

[Footnote 17: Osborn, Henry Fairfield, "Dinosaur Mummy" Amer. Mus.
Jour. Vol. xi, pp. 7-11, illustrated, Jan. 1911.]

[Footnote 18: There is some doubt whether this was really the
condition during life. W.D.M.]

CHAPTER VIII.

THE BEAKED DINOSAURS (Continued.)

C. THE ARMORED DINOSAURS--STEGOSAURUS, ANKYLOSAURUS.

_Sub-Order Stegosauria._

This group of dinosaurs is most remarkable for the massive bony armor
plates, crests or spines covering the body and tail. They were more or
less completely quadrupedal instead of bipedal, with straight
post-like limbs and short rounded hoofed feet adapted to support the
weight of the massive body and heavy armature. Although so different
superficially from the bird-footed biped Iguanodonts they are
evidently related to them, for the teeth are similar, and the horny
beak, the construction of the pelvis, the three-toed hind foot and
four-toed front foot all betray relationship. From what we know of
them it seems probable that they evolved from Iguanodont ancestors,
developing the bony armor as a protection against the attacks of
carnivorous dinosaurs, and modifying the proportio