dering the shores but nevertheless containing
typical sea shells.

"The elaborate dental apparatus is such as to show clearly that
Trachodonts were strictly herbivorous creatures. The mouth was
expanded to form a broad duck-like bill which during life was covered
with a horny sheath, as in birds and turtles. Each jaw is provided
with from 45 to 60 vertical and from 10 to 14 horizontal rows of
teeth, so that there were more than 2000 teeth altogether in both
jaws.

"Among living saurians, or reptiles, the small South American iguana
_Amblyrhynchus_ may be compared in some respects with the Trachodons
notwithstanding the difference in size. These modern saurians live in
great numbers on the shores of the Galapagos Islands off the coast of
Chile. They swim out to sea in shoals and feed exclusively on seaweed
which grows on the bottom at some distance from shore. The animal
swims with perfect ease and quickness by a serpentine movement of its
body and flattened tail, its legs meanwhile being closely pressed to
its side and motionless. This is also the method of propulsion of
crocodiles when swimming.

"The carnivorous or flesh-eating dinosaurs that lived on land, such as
_Allosaurus_ and _Tyrannosaurus_, were protected from foes by their
sharp biting teeth, while the land-living herbivorous forms were
provided with defensive horns, as in _Triceratops_, sharp spines as
in _Stegosaurus_ or were completely armored as in _Ankylosaurus_.
Trachodon was not provided with horns, spines or plated armor, but it
was sufficiently protected from carnivorous land forms by being able
to enter and remain in the water. Its skin was covered with small
raised scales, pentagonal in form on the body and tail, where they
were largest, with smaller reticulations over the joints but never
overlapping as in snakes or fishes. A Trachodon skeleton was recently
found with an impression of the skin surrounding the vertebrae which
is so well preserved that it gives even the contour of the tail as is
shown in the illustration (fig. 32).

"During the existence of the Trachodonts the climate of the northern
part of North America was much warmer than it is at present, the plant
remains indicating a climate for Wyoming and Montana similar to what
now prevails in Southern California. Palm leaves resembling the
palmetto of Florida are frequently found in the same rocks with these
skeletons. Here occur also such, at present, widely separated trees as
the