The Dinosaurs of Wyoming - Wyoming State Geological Survey ...

CHAPTER X
Evidences of Disease and Inju1) Among
the Dinosaurs
The indications of pathological conditions among the bones
of the ancient dinosaurs are relatively rare, and consist. for
the most part. of insignificant disturbances; fractures. abscesses.
arthritides and a single tumor comprising the catalogue
of disease and injury among the dinosaurs.
An enormous fractured rib (Figure 12, d) of one of the
huge amphibious dinosaurs is on exhibition in Field Museum,
FIGURE 9.
Backbone joints, Nos. 17-21, of the Wyoming whip-tail dinosaur, Diplodocus longuS.
seen from the right side, showing fusion of the joints by a diseased process called
Spondylitis deformans. The series of bones pictured has an actual length of about five
feet. The opening seen in the lesion to the left allows an examination of the articular
surfaces which are unaffected by disease. A fortunate fracture through the second
lesion from the left shows the entire ends of the bones to be healthy. The disease forms
a ring-like growth by the ossification of the longitudinal ligaments through disease. At
this point the thirty-foot tail of the reptile reached the ground, and Osborn thought the
conjoined bones indicated a "resting point" in the tail when the animal reared up on
its hind legs like a kangaroo. Specimen in the American Museum of Natural History,
X. I-IS.-After Osborn.
associated with an unhealed fracture of an adjoining rib. This
was in the "thunder lizard," the largest of the amphibious
dinosaurs. The injury could only have come from a blow
by another dinosaur, or by a falling rock or tree.
Fractured limb bones are rare among dinosaurs, chiefly
because of the size of the bones. An upper arm bone of a
horned dinosaur found in Canada by Barnum Brown had suffered
an oblique fracture which became badly infected. A pus
sinus was formed and the bone did not heal. This is the first
indication of a subperiosteal abscess among the dinosaurs. and
is clear evidence of the presence of infective germs.
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