Intervertebral and Epiphyseal Fusion in the Postnatal Ontogeny of Cetaceans and Terrestrial Mammals

In this paper we studied three related aspects of the ontogeny of the vertebral centrum of cetaceans and terrestrial mammals in an evolutionary context. We determined patterns of ontogenetic fusion of the vertebral epiphyses in bowhead whale (Balaena mysticetus) and beluga whale (Delphinapterus leucas), comparing those to terrestrial mammals and Eocene cetaceans. We found that epiphyseal fusion is initiated in the neck and the sacral region of...