Description of Chlorarachniophytes:
Circumscription: Reticulate amoeboid organisms with cytoplasmic strands linking cell bodies, uniflagellated dispersal stage, with photosynthetic compartment formed from a eukaryotic algal symbiont probably derived from green algae. Recent molecular work suggests close relationship with the euglyphid filose testate Amoebae but in the absence of a synapomorphy and the ramicristate nature of the mitochondrial cristae; they are here kept separated, ranked up to level of division. Also, see cercomonads. Ultrastructural identity: Mitochondria with tubular cristae. Dictyosomes present. With concentric extrusomes. Flagella of flagellated stage without hairs, scales, or other excrescences, also without paraxonemal structures. Basal bodies anchored by microtubular roots. Plastids with variable number of thylakoids per lamella and with associated nucleomorph and with pyrenoids. Synapomorphy: None known but may be definable by the plastid symbiosis.