An assemblage of unicellular eukaryotic organisms, sometimes placed in the phylum Alveolata, that are believed to have common ancestry based on certain morphological similarities and molecular systematics. They comprise the ciliates (see Ciliophora), the apicomplexans (see Apicomplexa), and the dinoflagellates (see Dinomastigota). In spite of very diverse lifestyles, they all have flattened vesicles (alveoli) supporting the plasma membrane and forming a flexible pellicle. The alveolates and the stramenopiles together are now widely regarded as comprising the chromalveolates.
Subjects: Biological Sciences.