出典:Wikipedia
出典:『Wikipedia』 (2011/07/20 17:01 UTC 版)
The Fusulinida is an extinct order within the Foraminifera in which the tests (shells) are composed of tightly packed, secreted microgranular calcite. In advanced forms the test wall is differentiated into two or more layers. Loeblich and Tappan, 1988, gives a range from the Lower Silurian to the Upper Permian, although in the Treatise, 1964, it is given from the Ordovician to the Triassic.