dinoflagellate sulcus dinoflagellate sulcal notch dinoflagellate sulcus notch A dinoflagellate sulcus that extends all the way to the posterior end of the cell (also known as antapex). The presence of a sulcal notch makes the dinoflagellate hypocone appear bilobed. sulcal notch 2014-06-27T16:28:49Z GO:0097618 pr The term name refers to a taxonomic group to make the label unique with respect to similarly-named anatomical structures. Also, the ventral (front) side of a dinoflagellate cell is the one where the sulcus is located (as opposed to the dorsal (back) side). The term 'sulcal notch' appears mostly in older literature; more recently, indication of a bilobed hypocone is used to express the same. cellular_component