[3] Although today it is commonly believed that many of the species described by Kofoid & Swezy are conspecific, their thorough and numerable descriptions of marine protists remain an admirable feat and a useful resource.

[11] Warnowia falls into the category of picoplankton, which constitutes a part of the picoeukaryotes community, and fills the ecological role of micro-consumers.

[12][13] In addition to being found in coastal waters worldwide, Warnowia has a dynamic role in the planktonic community of the oligotrophic, nutrient-poor Sargasso Sea.

[14] Seasonal shifts in Warnowia and other protists indicate a complex recycling food web in the Sargasso Sea, which helps to mitigate the low-nutrient availability of the open ocean.

The presence of Warnowia in nutrient-rich coastal ecosystems as well as nutrient-poor pelagic ones suggests that it can survive under a wide range of nutrient availabilities, though it is unknown how they can be so dynamic.

[1] Consequently, the sulcus, the groove that runs between the two hemispheres of the organism from the center of one side towards the posterior end of the cell, is twisted.

[4] Warnowia is characterized by a conspicuous photoreceptor organelle called the ocelloid located in the middle or posterior of the cell and directed ventral to anteriorly.

[1][4] Trichocysts, nematocysts, and pistons are absent, separating Warnowia from the closely related genera Nematodinium, Proterythropsis and Erythropsidinium.

[4] The nucleus is of the dinokaryon type, with continuously condensed chromosomes as in other Dinokaryote dinoflagellates,[1] and located in the middle or upper half of the cell.

[4] The ocelloid is a multilayered photoreceptor that is made up of subcellular components and is homologous to simpler eyespots found in other lineages of dinoflagellates.

[4][13] Structural details of the ocelloid, such as the number and morphology of hyalosome constriction rings can be used to distinguish different species of Warnowia.

[4] This group forms a well-supported clade within the order Gymnodiniales sensu stricto, however the taxonomy within the warnowiids is poorly understood and highly problematic since these species are very difficult to culture and rare in the wild.

In 2001, off the coast of Norway and Portugal, surface sediment samples were found to contain cysts that were identified as Warnowia rosea once germinated.