The Vossenveld Formation cropping out near Winterswijk in the Netherlands is well known because of its rich Middle Triassic marine reptile fauna assemblage. The aim of the study was to detect and examine bones with unusual shapes in order to identify the causes of their deformation, i.e., taphonomic, traumatic, or related to illness. The unusual, kinked shape of a sauropterygian humerus appears to result from taphonomic processes. Pathological changes were identified on a sauropterygian rib (osteofibrous dysplasia), large bone of uncertain identity (unusual coossification), and on the mandible of cf. Notosaurus marchicus (healed fracture). Despite hundreds of fossilized bones of marine reptiles found in Winterswijk, only few of them preserve pathologies, what may mean that sick or wounded individuals were quickly eliminated from the population.