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Annals of Medical History 



any kind in this region could easily occur. 

 Aside from possible blows from the head, 

 the dinosaur to which the above described 

 vertebrae belonged was entirely defenseless. 

 The tail, for example, might be seized by 

 one of the carnivorous dinosaurs and vig- 

 orously chewed for some time before the 

 owner of the tail was able to turn his huge 

 body and knock the offender away. 



Lesions of a similar nature, but not so well 

 developed, are known to occur in the tail of 

 Cetiosaurus Leedsi, an English dinosaur; and 

 Hatcher has described the same lesions in 

 the tail of Diplodocus. A fuller discussion of 

 these lesions is reserved for another time. 



The nature of the above-described lesion 

 is such that it may have been due to bac- 

 terial activity, and suggests, at any rate, 

 the presence of pathogenic bacteria in the 

 early part of the Cretaceous period. Bacteria 

 and primitive fungi have, indeed, been 

 described from much older periods. The 

 best account of their occurrence is con- 

 tained in "Microorganismes des combusti- 

 bles fossiles," by B. Renault. 34 Renault has 

 described and figured many forms of bac- 

 teria and fungi in the fossilized feces 

 (coprolites) of fishes, in fossil wood, and in 

 coal. He has also discovered in the teeth 

 of some ancient fishes what he regards as 

 indications of the activity of organisms 

 which have produced results similar to 

 caries. He shows in one of his plates photo- 

 micrographs of fossil bone from the petrified 

 feces in which the ravages of the bacteria, 

 Micrococcus are evident in the canaliculi 

 and the bone corpuscles, which appear in 

 various stages of destruction. 



Other deforming arthritides are repre- 

 sented by the arthritic condition sometimes 

 spoken of as rheumatoid arthritis which has 

 been noted by Virchow in the cave bears, 

 by other observers in certain fossil human 



34 B. Renault: "Microorganismes des combustibles 

 fossiles," Bull. Soc. de I'Industrie minerale Saint- 

 Etienne, Paris, 1899- 1900, Tomes 13-14, with folio 

 atlas of 20 plates of photomicrographs. 



skeletons, in the famous Lansing man of 

 Kansas, 35 and it is probably indicated in 

 the Cretaceous mosasaurs, where a well- 

 developed osteoma accompanied the arthri- 

 tic inflammation. 



4. Osteomyelitis is probably indicated 

 in the dinosaurian caudals figured herewith 

 and in certain phalangeal elements of a giant 

 wolf from the Pleistocene of California. 



5. Exostoses due to trauma, indicated 

 as callous growths around fractures of ribs 

 and limb bones, or as outgrowths due to 

 chronic irritation or infection, are fairly 

 common among fossil vertebrates. Healed 

 fractures (Fig. 7) are very common among 

 mammals and are occasionally seen among 

 fossil reptiles. Dinosaurs exhibiting broken 

 ribs, vertebrae, and horn cores attest the 

 accidents or fights which caused these 

 traumatic conditions, and has led Abel to 

 infer that the males of these animals con- 

 tested during the breeding season for the 

 female. An exostosis which is especially 

 clearly marked is evident on the inner or 

 visceral surface of a dinosaur scapula, where 

 it takes the form of a hook-like process, 

 evidently due to chronic irritation. An 

 exact duplicate of this lesion may be seen 

 on a recent human femur. One of the most 

 perfect exostoses is seen in a mosasaur from 

 the Cretaceous of Kansas where there is a 

 decided lump at the articular surface be- 

 tween the third and fourth dorsal vertebrae, 

 resulting in what is probably the only known 

 fossil osteoma. Curious exostoses which are 

 bilaterally symmetrical occur on the radii 

 of an Oligocene dog, the skeleton of which 

 is in the Carnegie Museum of Pittsburgh. 



7. Osteosarcomata have not been posi- 

 tively identified among extinct animals, but 

 the condition is suggested in several in- 

 stances. Esper, in 1774, described what he 

 thought was an osteosarcoma in the femur 

 of a cave bear, but Mayer, who studied 



35 Charles A. Parker: "Evidences of Rheumatoid 

 Arthritis in the Lansing Man," Amer. Geoi, 1904, 

 vol. xxxiii. pp. 39-42. fig. 1. 



