Bradyina

Bradyina is a genus of extinct foraminifera belonging to the order Fusulinida. These single-celled organisms possessed a characteristic coiled, multichambered test (shell) composed of calcium carbonate. Bradyina are significant index fossils, used in biostratigraphy to date and correlate sedimentary rock layers, particularly those of Carboniferous and Permian age. Their global distribution and relatively rapid evolutionary changes during these periods make them valuable for determining the age of rocks in which they are found. Morphological characteristics, such as the size, shape, and coiling pattern of the test, are used to differentiate between various species of Bradyina.