It can also reveal small plates in the vicinity of the flagellar bases that would not otherwise be observed. Peridinium cells, like most dinoflagellates, have a nucleus with permanently-condensed chromosomes that lack histones. Mitochondria have tubular cristae. The cytoskeleton is based on an asymmetrical array of two major microtubular roots arising from two flagellar bases. As in other dinoflagellates, a major membranous organelle, the pusule, is found in the vicinity of the flagellar bases.
Plastids have thylakoid membranes in groups of three.
Pyrenoids may or may not be present.