-Unicellular animal ranging in size from 0.1-8mm.
-Benthonic or planktonic forms with a considerable disparity in morphology within the suborder.
-Peaked in number in Early Carboniferous, already in prolonged decline throughout Permian.
-Already 90% extinct by P-T boundary, but last 10% was finished off by extinction event.
-Only fossils found in Triassic beds are derived from underlying beds.
