The family of Thalassiosiraceae have the unique quality of having a flat valve face.

These diatoms are common in brackish, nearshore, and open-ocean habitats, with approximately the same number of freshwater and marine species.

[2] Unlike naviculaceae who are symmetrical in shape some Thalassiosiraceae take on being tangentially undulate.

The species Thalassiosira pseudonana was chosen as the first eukaryotic marine phytoplankton for whole genome sequencing.

[3] T. pseudonana was selected for this study because it is a model for diatom physiology studies, belongs to a genus widely distributed throughout the world's oceans, and has a relatively small genome at 34 mega base pairs.