Dinosaurs | Page 9

its carcass. Some modifications were made in the position
to suit the exigencies of an open mount, and to accommodate the pose
to the particular action; the head of the animal was lifted a little, one
hind foot planted upon the carcass, while the other, resting upon the
ground bears most of the weight. The fore feet, used in these animals
only for fighting or for tearing their prey, not for support, are given
characteristic attitudes, and the whole pose represents the Allosaurus
devouring the carcass and raising head and fore foot in a threatening
manner as though to drive away intruders. The balance of the various
parts was carefully studied and adjusted under direction of the curator.
The preparation and mounting of the specimen were done by Mr. Adam
Hermann, head preparator, and his assistants, especially Messrs.
Falkenbach and Lang.
[Illustration: Fig. 12.--Restoration of Allosaurus by C.R. Knight. After
Osborn]
"As now exhibited in the Dinosaur Hall, this group gives to the
imaginative observer a most vivid picture of a characteristic scene in
that bygone age, millions of years ago, when reptiles were the lords of
creation, and 'Nature, red in tooth and claw' had lost none of her
primitive savagery, and the era of brute force and ferocity showed little
sign of the gradual amelioration which was to come to pass in future
ages through the predominance of superior intelligence."
Appearance and Habits of Allosaurus. A study of the mechanism of the

Allosaurus skeleton shows us in the first place that the animal is
balanced on the hind limbs, the long heavy tail making an adequate
counterpoise for the short compact body and head. The hind limbs are
nine feet in length when extended, about equal to the length of the body
and neck, and the bones are massively proportioned. When the thigh
bone is set in its normal position, as indicated by the position of the
scars and processes for attachment of the principal muscles (see under
Brontosaurus for the method used to determine this), the knee bends
forward as in mammals and birds, not outward as in most modern
reptiles. The articulations of the foot bones show that the animal rested
upon the ends of the metapodials, as birds and many mammals do, not
upon the sole of the foot like crocodiles or lizards. The flat vertebral
joints show that the short compact body was not as flexible as the
longer body of crocodiles or lizards, in which the articulations are of
the ball and socket type showing that in them this region was very
flexible. The tail also shows a limited flexibility. It could not be curled
or thrown over the back, but projected out behind the animal, swinging
from side to side or up and down as much as was needed for balance.
The curvature of the ribs shows that the body was narrow and deep,
unlike the broad flattened body of the crocodile or the less flattened but
still broad body of the lizard. The loose hung jaw, articulated far back,
shows by the set of its muscles that it was capable of an enormous gape;
while in the skull there is evidence of a limited movement of the upper
jaw on the cranial portion, intended probably to assist in the
swallowing of large objects, like the double jointed jaw of a snake.
As to the nature of the skin we have no exact knowledge. We may be
sure that it had no bony armor like the crocodile, for remains of any
such armor could not fail to be preserved with the skeletons, as it
always is in fossil crocodiles or turtles. Perhaps it was scaly like the
skin of lizards and snakes, for the horny scales of the body are not
preserved in fossil skeletons of these reptiles. But if so we might expect
from the analogy of the lizard that the scales of the head would be
ossified and preserved in the fossil; and there is nothing of this kind in
the Carnivorous Dinosaurs. We can exclude feathers from
consideration, for these dinosaurs have no affinities to birds, and there
is no evidence for feathers in any dinosaur. Probably the best evidence

is that of the Trachodon or duck-billed dinosaur although this animal
was but distantly related to the Allosaurus. In Trachodon (see p. 94),
we know that the skin bore neither feathers nor overlapping scales but
had a curiously patterned mosaic of tiny polygonal plates and was thin
and quite flexible. Some such type of skin as this, in default of better
evidence, we may ascribe to the Allosaurus.
[Illustration: Fig. 13.--View in the Hell Creek badlands in central
Montana, where the Tyrannosaurus skeleton was found.]
As to its probable habits, it is safe to infer (see p. 33), that it was