Besides the normal sea, foraminifers inhabit some littoral-marginal environments such as lagoons and estuaries, as well as inland relict seas left over by marine regression.

• 正>一、前言有孔虫是典型的海洋生物,在河湖等淡水水域和与海洋毫无关系的咸水湖沼里,都没有有孔虫,因此,它是海相和海陆过渡相及残留海的指相化石之一。