<jats:title>Abstract</jats:title><jats:p>Following a report of supposed fragments of calcareous dinoflagellate cysts from a Pleistocene drill core (CRP-1) recovered in the Ross Sea, Antarctica, sediments of the same core were re-investigated for their microfossil content. Besides common foraminifera and other microfossils, rare complete cysts of calcareous dinoflagellates were found. All cysts belong to the species <jats:italic>Caracomia arctica</jats:italic> (Gilbert &amp; Clark, 1983) Streng, Hildebrand-Habel &amp; Willems, 2002, a taxon characteristic of late Neogene high latitude, coldwater environments. Two morphotypes can be distinguished, <jats:italic>C. arctica</jats:italic> f. <jats:italic>arctica</jats:italic> and <jats:italic>C. arctica</jats:italic> f. <jats:italic>rossensis</jats:italic>, of which the latter is described as a new form. The presence of <jats:italic>C. arctica</jats:italic> strengthens diatom-based palaeoenvironmental reconstructions of periodical sea ice-free conditions at the time of deposition. Accordingly, cysts of <jats:italic>C. arctica</jats:italic> are interpreted as resting cysts that allow survival during harsh intervals of the high latitude environment. Previously reported calcareous dinoflagellates cyst fragments from these sediments are re-interpreted as test fragments of bilamellar foraminifera, which represent the most common group of foraminifers in the sediments.</jats:p>