Ornithocercus thumii is a species of Dinophyceae in the family Dinophysiaceae. They are native to Rio De Janeiro, Bahia, Rio Grande Do Sul, Espirito Santo, Rio Grande Do Norte, and SãO Paulo.
Definition: Living in the fluid medium (water or air) but unable to maintain their position or distribution independently of the movement of the water/air mass (adapted from Lincoln et al., 1998).