Fusulina, Print, The Fusulinida is an extinct order within the Foraminifera in which the tests (shells) are composed of tightly packed, secreted microgranular calcite. Like all Forams, they are single-celled organisms. 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, with the fusulinid foraminifera going extinct with the Permian–Triassic extinction event. While the latter is true, a more supported projected timespan is from the Mid-Carboniferous period.
Fusulina, Print, The Fusulinida is an extinct order within the Foraminifera in which the tests (shells) are composed of tightly packed, secreted microgranular calcite. Like all Forams, they are single-celled organisms. 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, with the fusulinid foraminifera going extinct with the Permian–Triassic extinction event. While the latter is true, a more supported projected timespan is from the Mid-Carboniferous period.