The
turtles vary widely in size, from species of only 6 inches
( 15 cm ) ( like for example North American box turtle
) , to the giant sea turtle leatherback, which may attain
a length of about 8 ft ( 2.4 m ).
The
upper shell of the turtle is called the carapace, and
the lower is called the plastron, and due to adaptive
changes and mode of life , their structure vary among
different turtle species.
