A study conducted by researchers from the Museum für Naturkunde in Berlin revealed the evolution of ossification patterns in the backbones of four-legged vertebrates. Antoine Verrière and his colleagues were able to reconstruct the patterns of how the bones in the vertebral column formed in the ancestor to all land vertebrates based on a large dataset of modern and fossil vertebrates with the inclusion of rare new data from the 300 Ma old reptile Mesosaurus tenuidens. The results are published this week in Scientific Reports.