In females, the hind flipper is used during nesting to excavate a 'flask shaped' hole in the sand in which she will lay her eggs. The pelvic bone is made up of a number of fused bones. Sea turtle skulls vary depending upon their diet and way of life although they all have the same basic bone pattern. Green turtle outlines. Click on the skull photographs for a full scale view.
All vertebrates have a backbone or vertebral column.
This backbone acts as a girder carrying the weight of the organs of the body. The backbone is made up of vertebrae separated by discs made of cartilage. There are five types of vertebrae although these are reduced and considerably modified in the sea turtles. There are 8 bony parts to the cervical or neck region, which is short when compared to many other reptiles. The neck is said to be retractile although sea turtles cannot pull their heads fully back into their shells.