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The Dinosaurs
The Dinosaurs (or "terrible reptiles"), the monarchs of the land
and the swamps, are the central and outstanding family of the
Mesozoic reptiles. As the name implies, this group includes most
of the colossal animals, such as the Diplodocus, which the
illustrated magazine has made familiar to most people.
Fortunately the assiduous research of American geologists and
their great skill and patience in restoring the dead forms enable
us to form a very fair picture of this family of medieval giants
and its remarkable ramifications.
The Diapsid reptiles of the Permian had evolved a group with
horny, parrot-like beaks, the Rhyncocephalia (or "beak-headed"
reptiles), of which the tuatara of New Zealand is a lingering
representative. New Zealand seems to have been cut off from the
southern continent at the close of the Permian or beginning of
the Triassic, and so preserved for us that very interesting relic
of Permian life. From some primitive level of this group, it is
generally believed, the great Dinosaurs arose. Two different
orders seem to have arisen independently, or diverged rapidly
from each other, in different parts of the world. One group seems
to have evolved on the "lost Atlantis," the land between Western
Europe and America, whence they spread westward to America,
eastward over Europe, and southward to the continent which still
united Africa and Australia. We find their remains in all these
regions. Another stock is believed to have arisen in America.
Both these groups seem to have been. more or less biped, rearing
themselves on large and powerful hind limbs, and (in some cases,
at least) probably using their small front limbs to hold or grasp
their food. The first group was carnivorous, the second
herbivorous; and, as the reptiles of the first group had four or
five toes on each foot, they are known as the Theropods (or
"beast-footed" ), while those of the second order, which had
three toes, are called the Ornithopods (or "bird-footed"). Each
of them then gave birth to an order of quadrupeds. In the
spreading waters and rich swamps of the later Triassic some of
the Theropods were attracted to return to an amphibiOus life, and
became the vast, sprawling, ponderous Sauropods, the giants in a
world of giants. On the other hand, a branch of the vegetarian
Ornithopods developed heavy armour, for defence against the
carnivores, and became, under the burden of its weight, the
quadrupedal and monstrous Stegosauria and Ceratopsia. Taking this
instructive general view of the spread of the Deinosaurs as the
best interpretation of the material we have, we may now glance at
each of the orders in succession.
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