Alveolates with flattened subsurface alveoli, an apical complex generally consisting of one or more polar ring(s), rhoptries, micronemes, a conoid, and subpellicular microtubules, present at some stage in the life cycle; sexuality where reported is by syngamy. Mostly the apicomplexan sporozoa, but colpodellids are free-living and predatory, and perkinsids are parasitic with flagellates dispersal stages.