Tuberculosis-like infectious spondylitis in a cervical vertebra of a plesiosaur from the Upper Cretaceous of Patagonia, Argentina

• Autores: Talevi, Marianella; Rothschild, Bruce; Mitidieri, Matías; Fernández, Marta Susana
• Año de publicación: 2021
• Idioma: inglés
• Tipo de recurso: documento de conferencia
• Materia: Ciencias Exactas y Naturales; Tuberculosis; Infectious; Cretaceous; Patagonia; Argentina; Ciencias Exactas y Naturales
• Institución: Universidad Nacional de Río Negro

Fil: Talevi, Marianella. Universidad Nacional de Río Negro, Instituto de Investigación en Paleobiología y Geología. Río Negro, Argentina.
Fil: Rothschild, Bruce. Carnegie Museum. Estados Unidos.
Fil: Mitidieri, Matías. Universidad Nacional de Río Negro, Instituto de Investigación en Paleobiología y Geología. Río Negro, Argentina.
Fil: Fernández, Marta Susana. CONICET, División Paleontología Vertebrados, Facultad de Ciencias Naturales y Museo. La Plata, Argentina.
Paleopathological studies have been used to understand the history of injury and disease in extinct populations, their putative cause, and on this basis, some infer paleoecology and behavioral aspects. Paleopathologies are generally identified if they damage the skeleton. The most common in the zoological/paleontological record are traumatic injuries, post-traumatic malformations, modification of bone tissue from infection, congenital defects, and neoplasms. Although pathologies in plesiosaurs are recognized since the 1870s, and various diseases have been reported (e.g., septic necrosis, avascular necrosis, erosive osteoarthritis, vertebral fusion, and tooth-marked bones), reports of infectious diseases are still comparatively scarce. Here we report the pathological cervical vertebra of a plesiosaur recovered from the Maastrichtian (Late Cretaceous) of Argentinian Patagonia. The specimen MML-PV 1305 is explored macroscopically and by computerized microtomography. The anterior external surface shows a taphonomic artifact (in the form of cracks in the subchondral bone with central loss) as well as an elliptical, subchondral erosion with minimal new bone formation and a slight adjacent filigree reaction. The right anteroventral surfaces of the centrum bears an erosive process with a minimal bone reaction and alterations have the appearance of space-occupied masses. On the left anteroventral surface of the centrum, there are abnormal vascular channels, associated with a groove just ventral to the articular surface. X-ray examination reveals a central lytic area with weakened and collapsed trabecular bone. The combination of these features indicates that the pathological aspect of the vertebra is due to an infection. The pattern of bone abnormalities is indistinguishable from that described in Pleistocene mammal skeletons affected by the granulomatous tuberculosis infection and analogous to the abnormal ribs and cervical vertebrae of an eosauropterygian from the Middle Triassic. The latter is also identified as turberculosis-like pneumonia. The case reported herein represents the first record of tuberculosis-like infection in a plesiosaur. As the vertebra was not part of an associated skeleton, it cannot be determined if the cause of death of the plesiosaur is unrelated or secondary due to compromised hunting ability (due to limited neck mobility) or the result of infection-related organ failure.