Definition
A plastron is the nearly flat part of the shell structure of a turtle, what could be called its belly shell π’. It's the ventral (lower) counterpart to the carapace (upper shell). Think of it as the turtle's underside protection. Unlike the carapace, the plastron is usually flatter and less ornate. Together, the carapace and plastron form a complete protective shell. The plastron protects the turtle's vital organs from below.