• Neoceratium macroceros: (Cleve) F.Gómez, D.Moreira e P.López-Garcia (2010)
• Ceratium macroceros: (Ehrenberg) Vanhöffen (1897)

The cell is thecate,  of large dimensions, solitary. the body of the cell is dorso-ventrally flattened and the horns are divergent. The rounded epitheca is prolonged into a long thin apical horn, slightly curved to the right. The hypotheca is prolonged into two antapical horns of the same width with divergent extremities, which originate from the posterior edges of the body of the cell, but after the curve point forwards, almost parallel to the apical horn. On the ventral side the central plates are very delicate. The cell contains numerous yellow-brown chloroplasts, and the nucleus is situated in the apical horn.

Cosmopolitan, typical of coastal and oceanic waters, from cold to temperate, but also reported in tropical waters.

Distribution: as Ceratium macroceros: Europe: Great Britain (Parke & Dixon 1976), Croatia (Vilicic et al. 2009 ), Ireland (McDermott & Raine 2006); Atlantic Islands: Canary Islands (Gil-Rodríguez et al. 2003); North America: Nova Scotia (Kim, Garbary & McLachlan 2004).

Phytoplankton dynamics in Pomquet Harbour, Nova Scotia: a lagoon in the southern Gulf of St., Lawrence. Phycologia 43, Kim K.Y., Garbary D.J., McLachlan J.L., 2004, 311-328.

Neoceratium gen. nov., a new genus for all marine species currently assigned to Ceratium (Dinophyceae)., Protist 161, Gómez F., Moreira D. e López-Garcia P., 2010, 35-54

Check-list of British marine algae - third revision., Journal of the Marine Biological Association of the United Kingdom 56, Parke M., Dixon P.S., 1976, 527-594.

Composition and annual cycle of phytoplankton assemblages in the northeastern Adriatic Sea., Botanica Marina 52(4), Vilicic, Djakovac, Buric, Z. & Bosak, 2009, 291-305.

The dinoflagellate genus Ceratium in Irish shelf seas., Galway: Martin Ryan Institute., McDermott G., Raine R., 2006, pp. [viii] + 1-86

Proctoctista. In: Lista de especies marinas de Canarias (algas, hongos, plantas y animales). (Moro, L., Martín, J.L., Garrido, M.J. & Izquierdo, I. Eds), Las Palmas: Consejería de Política Territorial y Medio Ambiente del Gobierno de Canarias., Gil-Rodríguez M.C., Haroun R., Ojeda Rodríguez A., Berecibar Zugasti E., Domínguez Santana P., Herrera Morán B., 2003, 5 - 30