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Re: Dilophosaurus Forelimb Bone Maladies
Bone abnormalities are common in theropod dinosaur skeletons, but
before now no specimen was known with more than four afflicted bones
of the pectoral girdle and/or forelimb. Here we describe the pathology
of a specimen of the theropod dinosaur Dilophosaurus wetherilli with
eight afflicted bones of the pectoral girdle and forelimb. On its left
side the animal has a fractured scapula and radius and large
fibriscesses in the ulna and the proximal thumb phalanx. On its right
side the animal has abnormal torsion of the humeral shaft, bony tumors
on the radius, a truncated distal articular surface of metacarpal III,
and angular deformities of the first phalanx of the third finger.
Healing and remodeling indicates that the animal survived for months
and possibly years after its ailments began, but its right third
finger was permanently deformed and lacked the capability of flexion.
The deformities of the humerus and the right third finger may be due
to developmental osteodysplasia, a condition known in extant birds but
unreported in non-avian dinosaurs before now.
Ok, from what I read in other responses was that the forelimbs were't
necessarily used in predation, and that these injuries did not result in
The paper says this is UCMP 37302
and that they did a surface examination of this fairly complete
specimen. No other injuries were reported, but I wonder if it is
possible that there were if the whole skeleton was not accessible.
A fight of some kind is certainly possible if not probable, but another
cause suggested itself to me, and that is that it took a bad fall while
running. A face plant, as it were, and the forelimbs injured while
hitting the ground. If so then the jaw should exhibit injury too.
What I read is that the skull was incomplete when found, and the 1954
paper is not accessible to me so I couldn't tell if the skull might
indeed have suffered some injury.