Vertebral lesions in a titanosaurian dinosaur from the Lower-Upper Cretaceous of Brazil

Abstract

In this paper we describe macroscopically two types of bone lesions on a caudal vertebra of an indeterminate titanosaur recovered from the Lower-Upper Cretaceous (Albian-Cenomanian) Açu Formation in the Potiguar Basin, Brazil. The first type of lesion corresponds to cystic lesions on cranial and caudal joint surfaces of the vertebral body, which are identified as subchondral cysts. The second type of lesion corresponds to an irregular bone overgrowth located on longitudinal ligament insertion points. This ossification can be associated with an axial spondyloarthropathy or diffuse idiopathic skeletal hyperostosis (DISH). Bone overgrowth on vertebrae is well documented in the dinosaur fossil record, whereas this is only the second case recorded of subchondral cysts.