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.
Pages:
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41