The plastron is the nearly flat part of the shell structure of a tortoise, what we would call the belly, similar in composition to the carapace; with an external layer of horny material divided into plates called scutes and an underlying layer of interlocking bones. In certain families there is a hinge between the pectoral and abdominal scutes allowing the turtle to almost completely enclose itself. In certain species the sex of a testudine can be told by whether the plastron is concave, male; or convex, female. This is because of the mating position.
The plastron is the nearly flat part of the shell structure of a tortoise, what one would call the belly, similar in composition to the carapace; with an external layer of horny material divided into plates called scutes and an underlying layer of interlocking bones.
Turtle plastrons were used by the ancient Chinese in a type of divination called plastromancy.
A "plastron" is also a thin permanent layer of air around the body of some aquatic insects, held in place by hydrophobic hairs, and acting as a physical gill.
Plastromancy (from plastron + Greek μαντεία, "divination") is a form of pyromantic divination using the plastron, or undershell of a turtle.
The plastrons were first prepared through the boring of shallow pits partway through the interior (flesh-side) surface.
During the Shāng dynasty, the date, diviner's name and topic of divination were generally written on the plastron, sometimes along with prognostications.
Feeds |
Contact