In many marinecreatures, however, the skeleton is composed of a mineral variety of calcium carbonate called aragonite.
然而，很多海洋生物的骨骼由一种叫作霰石的碳酸钙矿物变体组成。
2
X-ray examination of thin slabs of rock sometimes reveals the ghostly outlines of tentacles, digestive tracts, and visual organs of a variety of marinecreatures.
对岩石薄片的 X 射线检查有时会发现可怕的触角轮廓、消化道和很多种海洋生物的视觉器官。
3
That is bad because many Marinecreatures rely on shells made of calcium carbonate to protect themselves.