Pathology on caudal vertebra of Glyptodon sp. (Xenarthra, Cingulata) from the Upper Pleistocene (Luján Formation) of Buenos Aires province (Argentina)

Abstract

The paleontological collection of the Museo Municipal de Ciencias Naturales “Carlos Ameghino” (MCA, Mercedes, Buenos Aires Province, Argentina) includes hundreds of mammalian fossil specimens collected from the Luján Formation (Lujanian Stage/Age), bounded to the Late Pleistocene/Early Holocene. Among the specimens of the MCA collection, a caudal vertebra (MCA-117) of Glyptodon sp. (Xenarthra, Cingulata) with pathologies was identified, which are here characterized in order to perform a diagnosis. The main alterations in the vertebra consist of bone erosion and remodeling in the left transverse process, bone erosion in the vertebral centrum, and deformation in the neural arch affecting the prezygapophyses. The features identified in the transverse process were diagnosed as bone remodeling, alterations previously described for Pleistocene xenarthrans. The erosions observed in the vertebral centrum are comparable to spondylosis, Schmorl´s node, intervertebral discopathies, or, alternatively, calcium pyrophosphate deposition disease. Nonetheless, these could potentially manifest as secondary complications arising from spondylosis. Regarding characteristics such as low bone density, it is concluded that they are indicative of modifications due to osteoporosis. The alterations present in the specimen can be compared with bone pathologies recognized in elderly individuals with large body mass.