530 R. L. Moodie — Y&rtehrce of a Dinosaur 



Art. XXXYI. — Two Caudal Yertebrce of a Sauropodous 

 Dinosaur Exhibiting a Pathological Lesion; by Hoy L. 

 Moodie. 



The assistance which paleontology may render students of 

 disease is instanced by the following discussion of a pathological 

 lesion involving two caudal vertebrae of a sauropodous dino- 

 saur from the Como Beds of Wyoming. The specimen is the 

 property of the Kansas University Museum and I am indebted 

 to Mr. H. T. Martin for the privilege of describing it. 



So far as the present writer is aware, the occurrence of 

 pathological processes in fossil vertebrates have been described 

 only as incidents in connection with the descriptive anatomy 

 of the forms. Abel* has, to be sure, given a short discussion 

 of evidences of disease in fossilized bones. Fossil bones 

 exhibiting these interesting features of ancient disease are not 

 commonly seen in our collections. Yet such as do occur 

 should be described so that those students of medicine who are 

 interested in the origin of disease may have the opportunity 

 to examine the evidence afforded by paleontology. Broken 

 ribs, fractured limb bones, and injured vertebrae, a part or all 

 of which show evidence of disease, may occasionally be seen 

 and should be described. 



An examination of the figure reveals a lesion not unfamiliar 

 to students of modern pathology. It has the appearance of a 

 spongy growth surrounding the intervertebral articular surfaces, 

 and involving the spinous processes of these two caudal ver- 

 tebrae. The normal form of the vertebrae is well known to 

 readers of this journal and the large amount of pathological 

 growth is evident. The mass resembles closely the tumor-like 

 masses of oak trees. It entirely encircles the vertebrae and has 

 involved fully half of the two bones. All evidence of separate 

 structure is obliterated and the vascular canal of the chevron 

 has been filled by the bony matter, and the chevron has been 

 pushed far out of its normal position. 



The specimen has a length of 26 - 5 cm and a weight of 5 - l kg. 

 The circumference of the normal articular surface is 2T cm , and 

 the same measurements around the middle of the tumor-like 

 mass is 38 - 5 cm . The surface of the lesion is rather deeply pit- 

 ted, and the mass is asymmetrical, having attained greater 

 dimensions on one side than on the other. 



The enlargement is somewhat suggestive of the lesion of 

 chronic osteomyelitis. It may be a callous growth due possibly 

 to a fracture of the caudal vertebrae; or it may be a bone 



*Abel, 0., 1912, Paleobiologie, pp. 91-95. 



