NEW PALEOPATHOLOGICAL INFORMATION ABOUT OTHNIELOSAURUS PES (LATE JURASSIC, USA)

PENÉLOPE CRUZADO CABALLERO; MALCOLM BEDELL; DÍAZ-MARTÍNEZ, IGNACIO; XABIER PEREDA-SUBERBIOLA; BRUCE ROTHSCHILD

Congreso; Reunión de Comunicaciones de la Asociación Paleontológica Argentina; 2019

The study of palaeopathologies offers valuable information about the historical record of the injuries and behaviour of organisms in the past. The record of pathological bones of dinosaurs is more abundant in the axial and appendicular areas than in other areas of the body. Here, the injuries recorded in the almost complete left pes of the neornitischian Othnielosaurus consors (Marsh, 1878) (YPM VP 1882; Wyoming, USA) are described. Othnielosaurus shows pathological features in all its pes digits. Three types of pathologies have been identified: calcium pyrophosphate deposition disease, pilon fractures and impact fractures. Calcium pyrophosphate deposition disease (CPPD) is visible on the articular surface of phalange II-3 as a small osseous plaque. The pilon fracture, evidenced by the growing of a callous tissue in the shaft of the phalange I-1, was produced by high energy impact and was healed before death. The impact fractures have been identified as focal subsidence, partly healed in the articular surfaces of phalanges III-1 and IV-4. This resulted in a damage mimicking osteochondrosis. The set of palaeopathologies recorded in Othnielosaurus, which are in different stages of healing, would likely generate discomfort in the way of movement (limp) and probably affect its lifestyle. Therefore, it is possible that the unhealed impact fracture affects the feeding and locomotion capacity and contributed to the death of this Othnielosaurus individual.