Tortoises seem to preferentially put the available calcium in the plastron. 龟们似乎更喜欢把可用的钙质添加到他们的胸甲中。
Because the plastron has a hinge between the pectoral and abdominal scutes the flexibility endowed by the ligaments allows these turtles to close up very tightly. 由于胸甲和腹甲之间具有铰链关节，可以通过韧带活动，所以它们可以将自己牢牢地闭起来。
