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

Abstract

Provide a frame of reference for the recognition and interpretation of bezoars recovered from archeologicaland paleontological sites. 49 bezoars from extant guanaco (Lama guanicoe) were analyzed and compared with five objectspreviously identified as bezoars, recovered from Holocene archeological sites of the Argentine Pampas. Size, shape, weight, external and internal features, and mineralogical composition were evaluated inboth modern and archeological bezoars using nondestructive and destructive methods. Modern and archeological bezoars are formed by calcium phosphate and display great morphologicalvariability linked to ante-mortem processes, taphonomic alterations, and anthropic activity. Morphometry, along with external and internal features and mineral composition, are useful toolsfor the identification and interpretation of bezoars in the fossil record. This study offers new information on the etiology, mechanisms of formation, and means of interpretingthe presence of bezoars, a common pathology in South American camelids, in the fossil record. The features of fossil bezoars do not provide accurate identification of the animal that producedthem. Further analyses on modern bezoars belonging to other species of mammals areneeded in order to enhance the interpretation of bezoars in the fossil record.