Table 2 Morphological features of warnowiid dinoflagellate genera.
| Â | Nematodinium 1 | Proterythropsis 2 | Warnowia 3 | Erythropsidinium 4 | Greuetodinium 5 |
|---|---|---|---|---|---|
ocelloid | Â | Â | Â | Â | Â |
position in the cell | posterior | posterior | ~cell middle or posterior | anterior | Anterior |
directed | ventral | ventral | ventral to anteriorly | anteriorly | Anteriorly |
relative size | small | small | medium | large | very large |
# constriction rings | 1 | ? | 2 | 3 | ? |
'pigment ring' | band, continuity with upper retinal body | ? | ring, isolated from retinal body | ring, totally independent from retinal body | ? |
# per cell | 1 | 1 | 1 | 1 (or 2*) | ~15 lenses |
| Â | integrate type | integrate type | integrate type | integrate type | composite type |
nematocysts | yes (and no, see Hulburt 1957 | yes (and no, see Kofoid & Swezy 1921) | no | no (but see Hertwig 1884) | no |
feeding apparatus | ? | ? | ? | stomopharyngian complex | ? |
chloroplasts | yes and no | no | no (but see Hulburt 1957) | no | no |
nucleus position | upper cell half | upper cell half | middle or upper cell half | right upper cell half | median upper cell half |
acrobase | outward left spiral, 1 turn (or little more) = loop in Gymn. s.s. | outward left spiral, 1 turn (or little more) = loop in Gymn. s.s. | inward left spiral, 1.5–2.0 turns, some species plus outward left spiral | angled left 'spiral', 2 turns | ? (ventral below the cingulum) |
cingulum | ~1.5–2.25 turns | ~1.25–2.0 turns | ~1.0–2.5 turns | 1.5 turns | 1 turn, steep descending dorsally |
sulcus | < 1–2.0 turns | < 1 turn | 0.5–1.75 turns | straight | nearly one turn |
cell 'extension' (tentacle) | no | yes | no | no | ? maybe |
piston | non | non | non | 1 (seldom 2*) | 1 |
terminal stylet | - | - | - | sometimes | ? |