EuroTurtle - turtle life cycle

Structure of the skeleton

Plastron: Lower bony plate

Epiplastron:

The foremost pair of bony plates of the lower bony shell or plastron.

Entoplastron:

The middle bony plate of the lower bony shell or plastron.

Hyoplastron and Hyoplastron:

The middle two pairs of bony plates of the lower bony shell or plastron. The hyoplastron is the pair of bony plates nearer to the head. These two pairs of bones are often known as the bridge bones and form the main part of the lower bony shell or plastron.

Xiphiplastron:

The rearmost bones of the lower bony shell or plastron.