Fusulinida

Fusulinida
Temporal range: Lower Pennsylvanian–Upper Permian
Scientific classification Edit this classification
Domain: Eukaryota
Clade: Diaphoretickes
Clade: SAR
Phylum: Retaria
Subphylum: Foraminifera
Class: Globothalamea (?)
Order: Fusulinida
Superfamilies

Archaediscacea
Colaniellacea
Earlandiacea
Endothyracea
Fusulinacea
Geinitzinacea
Moravamminacea
Nodosinellacea
Palaeotextulariacea
Parathuraminacea
Ptychocladiacea
Tetrataxacea
Tournayellacea

Fusulinid limestone, Upper Pennsylvanian; Elk County, Kansas. Field of view is 3.9 cm wide. Link at source to view of entire slab.

The Fusulinida is an extinct order within the Foraminifera in which the tests are traditionally considered to have been composed of microgranular calcite. Like all forams, they were single-celled organisms. In advanced forms the test wall was 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.