Calcareous dinoflagellate cysts or calcareous dinocysts are dinoflagellate cysts produced by a group of peridinoid dinoflagellates, called calcareous dinoflagellates.
Definition
Organisms producing calcareous structures are exclusively found in a small group of peridinoid dinoflagellates, called calcareous dinoflagellates. Such calcareous structures are either dinocysts (systematized as CalciodinelloideaeFensome, R.A., Taylor, F.J.R., Norris, G., Sarjeant, W.A.S., Wharton, D.I., Williams, G.L., 1993. A classification of living and fossil dinoflagellates. Micropalaeontology (Special Publication) 7, 1–245.), which are formed during the life cycle (i.e., mostly hypnozygotes, after sexual reproduction, or resting stages; an overview of potential cyst formations is given by) or found in vegetative stages (namely in Thoracosphaera Kamptner). The potential to produce calcareous structures has been considered as apomorphic within alveolates,Kohring, R., Gottschling, M., Keupp, H., 2005. Character traits and palecological significance of calcareous dinoflagellates—an overview. Paläont. Z. arguing for the monophyly of Calciodinellaceae (including ThoracosphaeraWall, D., Dale, B., 1968. Quaternary calcareous dinoflagellates (Calciodinelloideae) and their natural affinities. J. Paleont. 42, 1395–1408Janofske, D., 1992. Kalkiges Nannoplankton, insbesondere kalkige Dinoflagellaten-Zysten der alpinen Ober-Trias: Taxonomie, Biostratigraphie und Bedeutung für die Phylogenie der Peridiniales. Berliner Geowiss. Abh. (E) 4, 1–53.).
Distribution and ecology
Calciodinellaceae (Peridiniales, Dinophyceae) comprise 35 extant species of calcareous dinophytes,Zonneveld, K. A. F., Meier, K. J. S., Esper, O., Siggelkow, D., Wendler, I., & Willems, H. (2005). The (palaeo-)environmental significance of modern calcareous dinoflagellate cysts: A review. Paläontologische Zeitschrift, 79, 61–77. plus about 260 fossil species.Fensome, R. A., & Williams, G. L. (2004). The Lentin and Williams index of fossil dinoflagellates. College Park: American Association of Stratigraphic Palynologists.Streng, M., Hildebrand-Habel, T., & Willems, H. (2004). A proposed classification of archeopyle types in calcareous dinoflagellate cysts. Journal of Paleontology, 78, 456–483. They are distributed in cold through tropical seas of the world (neritic and pelagic).Gottschling M, Keupp H, Plötner J, Knop R, Willems H, Kirsch M (2005a) Phylogeny of calcareous dinoflagellates as inferred from ITS and ribosomal sequence data. Mol Phylogenet Evol 36:444–455 Calcareous cysts are deposited in both marine sediments that are coastalMontresor, M., Zingone, A., Sarno, D., 1998. Dinoflagellate cyst production at a coastal Mediterranean site. J. Plankton Res. 20, 2291–2312.Persson, A., Godhe, A., Karlson, B., 2000. Dinoflagellate cysts in recent sediments from the west coast of Sweden. Bot. Mar. 43, 69–79. and oceanic.Vink, A., 2004. Calcareous dinoflagellate cysts in South and equatorial Atlantic surface sediments: Diversity, distribution, ecology and potential for palaeoenvironmental reconstruction. Mar. Micropaleontol. 50, 43–88. The first freshwater dinoflagellate that produces calcareous cysts was recently discovered.CRAVEIRO S.C., PANDEIRADA M.S., DAUGBJERG N., MOESTRUP Ø. AND CALADO A.J. 2013. Ultrastructure and phylogeny of Theleodinium calcisporum gen. et sp. nov., a freshwater dinoflagellate that produces calcareous cysts. Phycologia 52: 488–507.
Fossil record
According to the fossil record, calcareous dinoflagellates originate in the Upper Triassic and are highly diverse during the Cretaceous and throughout the Tertiary.Keupp, H., 1991. Fossil calcareous dinoflagellate cysts. In: Riding, R. (Ed.), Calcareous Algae and Stromatolites. Springer, Berlin, pp. 267–286.Willems, H., 1994. New calcareous dinoflagellates from the Upper Cretaceous white chalk of northern Germany. Rev. Palaeobot. Palynol. 84, 57–72.
Systematics
Due to their long stratigraphic range, many fossil species (namely their cysts) have been described. By contrast, descriptions of extant species are primarily based on the motile stages (namely on the thecae, which are less diverseLewis, J., 1991. Cyst-theca relationships in Scrippsiella (Dinophyceae) and related orthoperidinoid genera. Bot. Mar. 34, 91–106.Montresor, M., 1995. Scrippsiella ramonii sp. nov. (Peridiniales, Dinophyceae), a marine dinoflagellate producing a calcareous resting cyst. Phycologia 34, 87–91.). This has led to two distinct systematics: paleontological (with four subordinate groups, primarily based on the cyst wall ultrastructure, of which the c-axes of the crystals are orientated irregularly oblique, regularly radial, regularly tangential, or regularly oblique) and neontological (with the motile taxa Bysmatrum Faust and Steidinger, Ensiculifera Balech, Pentapharsodinium Indelicato and Loeblich III, and ScrippsiellaFaust, M.A., Steidinger, K.A., 1998. Bysmastrum gen. nov. (Dinophyceae) and three new combinations for benthic scrippsielloid species. Phycologia 37, 47–52Steidinger, K.A., Tangen, K., 1996. 3. Dinoflagellates. In: Tomas, C.R. (Ed.), Identifying Marine Diatoms and Dinoflagellates. Academic Press, San Diego (California), pp. 387–583.).
References