Roentgenographic indicators of skeletal maturity in marine mammals (Cetacea).

A new roentgenographic classification (grading) scheme is presented for utilization in studies of skeletal development and maturation in marine mammals, particularly cetaceans. This is based on adequate description of the extent of development and maturation of the various secondary ossification centers, their eventual patterns of fusion, and subsequent remodeling with the metaphysis. The six stages are illustrated schematically and roentgenographically. This scheme may be applied to any cetacean longitudinal bone developing proximal and distal epiphyseal ossification centers.