dinoflagellate

Any of an order (Dinoflagellata) of chiefly marine planktonic, usually solitary unicellular phytoflagellates that include luminescent forms, forms important in marine food chains, and forms causing red tide.

Dinoflagellates also help produce some of the oxygen we find in our atmosphere. They move via two uneven flagella (Latin; flagellum, flail, whip). Many forms, such as diatoms, have a shell made of cellulose or silica. They are argued by zoologists to be protozoans, and botanists to be algae.