Modern guanaco (Lama guanicoe, Camelidae) bezoars: An approach towards identification in the fossil record.

OBJECTIVE: Provide a frame of reference for the recognition and interpretation of bezoars recovered from archeological and paleontological sites. MATERIALS: 49 bezoars from extant guanaco (Lama guanicoe) were analyzed and compared with five objects previously identified as bezoars, recovered from Holocene archeological sites of the Argentine Pampas. METHODS: Size, shape, weight, external and internal features, and mineralogical composition were evaluated in both modern and archeological bezoars using nondestructive and destructive methods. RESULTS: Modern and archeological bezoars are formed by calcium phosphate and display great morphological variability linked to ante-mortem processes, taphonomic alterations, and anthropic activity. CONCLUSIONS: Morphometry, along with external and internal features and mineral composition, are useful tools for the identification and interpretation of bezoars in the fossil record. SIGNIFICANCE: This study offers new information on the etiology, mechanisms of formation, and means of interpreting the presence of bezoars, a common pathology in South American camelids, in the fossil record. LIMITATIONS: The features of fossil bezoars do not provide accurate identification of the animal that produced them. SUGGESTIONS FOR FURTHER RESEARCH: Further analyses on modern bezoars belonging to other species of mammals are needed in order to enhance the interpretation of bezoars in the fossil record.

Bone pathologies in a modern collection of guanaco (Lama guanicoe): Contributions to the interpretation of bone lesions in archeological contexts.

Research on animal paleopathology has significantly grown in the field of zooarchaeology during the last years. Usually bone lesions have been associated to specific activities carried out by animals. However, the etiology and prevalence of many bone abnormalities are still uncertain due to the scarcity of studies in modern reference collections. The aim of this study is to determine the postcranial skeletal lesions that characterize a population of wild camelids and to differentiate bone lesions related to human management of camelids. For this purpose, we analyze the health status of a modern collection of guanaco by recording a series of indicators and its manifestation in different anatomical units. The osteological sample comprises 54 guanacos from Cinco Chañares, San Antonio department, Rio Negro province, Argentina. The frequency of lesions by anatomical unit, sex, and age were studied in order to generate parameters for comparison with other samples of contemporary camelids and with zooarchaeological record. The analyzed sample is characterized by infectious, traumatic, degenerative and congenital abnormalities in low prevalence. The most common pathologies were degenerative origin. These were significantly more frequent among senile adults, and were differentiated of the ones registered among domestic camelids.