"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.
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