Ochrophyte classes

The Coscinodiscophyceae are a class of diatoms. They are similar to the Centrales, a traditional, paraphyletic subdivision of the heterokont algae known as diatoms. The order is named for the shape of the cell walls (or valves or frustules) of centric diatoms, which are circular or ellipsoid in valve view. The valves often bear radially symmetrical ornamental patterns that can appear as dots when viewed with an optical microscope. Some also bear spines on their valves, which may either increase cell surface area and reduce sinking, or act as a deterrent to zooplankton grazers. Unlike pennate d

Bolidophyceae is a class of photosynthetic heterokont picophytoplankton, and consist of less than 20 known species. They are distinguished by the angle of flagellar insertion and swimming patterns as well as recent molecular analyses. Bolidophyceae is the sister taxon to the diatoms (Bacillariophyceae). They lack the characteristic theca of the diatoms, and have been proposed as an intermediate group between the diatoms and all other heterokonts.

Dictyochophyceae sensu lato is a photosynthetic lineage of heterokont algae.

Fragilariophyceae is a group of pennate diatoms lacking a raphe.

Pelagophyceae is a class of heterokont algae. It is the sister group of the Dictyochophyceae.

Chrysomerophyceae is a proposed monotypic class of photosynthetic heterokont eukaryotes.

Synchromophyceae is a class of photosynthetic stramenopiles. The chloroplast of the Synchromophyceae are surrounded by two membranes and arranged in a way where they share the outer pair of membranes. The entire chloroplast complex is surrounded by an additional two outer membranes. ==Evolution== Synchromophyceae is a class within the Ochrophyta that contains a few genera of amoeboid organisms, such as the mixotrophic Synchromonas and the heterotrophic Chlamydomyxa and Leucomyxa. It is phylogenetically close to the classes Chrysophyceae and Picophagea, within the SII clade.