A Study in Paleopathology

Abstract

PALEOPATHOLOGY is that branch of comparative pathology which deals with evidences of diseases as found in the remains of ancient and extinct organisms. Pathological conditions have affected both animal and plant organisms from very early geological times. This phase of comparative pathology has been neglected; little has appeared in medical publications upon this subject and but little more in technical geological publications. It is not our intention to enter into a discussion of geology further than is shown in the accompanying chart (Fig. 1) which shows the various geological periods in their correct sequence and comparative lengths. A short examination of this chart will suffice to renew the memory as to the essential details. We wish in this presentation to call attention to the similarity of several pathological conditions in the earlier geological periods to those now in existence, and to the continuation of these conditions through these long periods of time. To this end we have made a study of such material as we have been able to obtain, have compared it with recent pathological conditions, and are presenting the results of our researches, with some of the original material, photographs, and roentgen films. The material of the Pleistocene Period of the Cenozoic Era is from the Rancho la Brea deposit, in Los Angeles, and shows excellent detail in films, it having been deposited in asphalt and thus preserved but not mineralized. The other material, from various sources and older geologically, is mineralized and can not be radiographed. Both types of material show clear evidences of definite pathological change. In some cases we have normal specimens for comparison with the pathologic. It is well recognized that many anatomical structures and physiological functions arose in the early geological periods and have persisted with but little change throughout the intervening ages, and we believe that many pathological conditions arose likewise, and that similarities of persistence, change, and modifications may be comparable to those of anatomy and physiology. Group No.1: Dental pathology; consists of mineralized specimens: No. 1. The mandible of a Mastodon, Trilophodon, of the Pliocene Period; fracture through the tooth socket, ununited, slight repair beginning. No. 2. Incisor tooth of a small camel of the Pliocene Period which shows caries, apical absorption, and osteo-dentine formation. No. 3. Fused deciduous and permanent teeth of Diceratherium Cookii, a rhinoceros of the Pliocene Period. No. 4. Fused decidous and permanent teeth of Aphelops, a rhinoceros of the Pliocene Period. Group No. 2: Dental pathology; consists of four specimens from the Pleistocene deposit in the Rancho la Brea pits, in Los Angeles, California, and with other material of this kind was obtained through the courtesy of the Los Angeles Museum of Natural History.