Fossil group

Fusulinids

Foraminifera · Carboniferous – Permian

Large, spindle- or grain-shaped foraminifera of the late Palaeozoic, with intricately partitioned tests. They were rock-forming on shallow tropical shelves and evolved rapidly, making them the premier index fossils of the Carboniferous and Permian before dying out in the end-Permian mass extinction.

A broad fossil group rather than a single taxon — the units below record it among their fauna or flora.