The phylogenetic relationships of calcareous dinoflagellates (i.e., Calciodinellaceae and Thoracosphaera) are investigated. Molecular data from the ribosomal 5.8S rRNA and highly conserved motifs of the ITS1 show Calciodinellaceae s.l. to be monophyletic when few non-calcareous taxa are included. They segregate into three monophyletic assemblages in a molecular analysis that considers the 5.8S rRNA and both the Internal Transcribed Spacer regions ITS1 and ITS2: a clade comprising species of Ensiculifera and Pentapharsodinium (E/P-clade), Scrippsiella s.l. (including fossil-based taxa such as Calciodinellum and Calcigonellum), and a heterogeneous group (T/P-clade) of calcareous (e.g., Thoracosphaera) and non-calcareous taxa (e.g., the highly toxic Pfiesteria). The potential to produce calcareous structures is considered as apomorphic within alveolates, and non-calcareous taxa nesting with calcareous dinoflagellates may have reduced calcification secondarily. Molecular results do not contradict general evolutionary scenarios provided by previous morphological (mainly paleontological) investigations.
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http://dx.doi.org/10.1016/j.ympev.2005.03.036 | DOI Listing |
Front Microbiol
July 2024
CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
Variation in the condition of marine sediments provides selective preservation milieus, which act as a key determinant for the abundance and distribution of dinoflagellate resting cysts in natural sediments. Microbial degradation is an understudied biological factor of potential importance in the processes. However, gaps remain in our knowledge about the fundamental information of the bacterial consortia associated with dinoflagellate resting cysts both in laboratory cultures and in the field.
View Article and Find Full Text PDFMar Environ Res
July 2024
Zentrum für Marine Umweltwissenschaften der Universität Bremen (MARUM), Leobener Str. 8, 28359, Bremen, Germany; Geosciences Department, University of Bremen, Klagenfurter Str., 28359, Bremen, Germany.
Our understanding of dinoflagellates' present-day and past ecology is limited due to the scarcity of data on the transport of dinoflagellate cysts in oceanic environments. Previous studies have shown that lateral transport affects the source-to-sink trajectory of cysts in the very productive region off Cape Blanc (NW Africa). Unsolved questions remain, such as: how far these cysts can be advected, whether the cyst sources vary over time and whether lateral transport is a permanent feature or restricted to individual events.
View Article and Find Full Text PDFThe Late Cretaceous was a unique period in the history of the Earth characterized by elevated sea levels, reduced land area, and significantly high concentrations of atmospheric CO resulting in increased temperatures across the globe-a 'Greenhouse World'. During this period, calcareous dinoflagellate cysts (c-dinocysts) flourished and became a ubiquitous constituent of calcifying plankton around the world. An acme in calcareous dinocysts during the Albian to the Turonian coincided with the highest recorded seawater surface temperatures and was possibly linked to conditions that favored calcification and a highly oligotrophic system in European shelf seas.
View Article and Find Full Text PDFSwiss J Geosci
December 2022
Department for Geology & Palaeontology, Universalmuseum Joanneum, Weinzöttlstraße 16, 8045 Graz, Austria.
Unlabelled: In the area of Bad Deutsch-Altenburg (Hainburg Mountains, Lower Austria) a Middle Miocene transgression over Mesozoic basement was explored in the course of the Danube power plant project "Hainburg". The Mesozoic basement forms a narrow ridge dipping to the northeast towards the Vienna Basin, covered by various Miocene sediments. The ridge represents a specific paleotopography that required a detailed study with 78 shallow, fully cored drill holes in an area of c.
View Article and Find Full Text PDFPLoS One
July 2024
Faculty of Geology, Geophysics, and Environmental Protection, AGH University of Science and Technology, Kraków, Poland.
Variegated limestones, a transitional series between red, Upper Jurassic radiolarite and whitish, Lower Cretaceous Maiolica limestone in the Pieniny Klippen Belt deposits in the Polish part of the Western Carpathians, have yielded rich microfossil assemblages with common calcareous dinoflagellate resting stages, hereafter, dinocysts. We found an undescribed dinocyst species in red-greenish limestone of a deep water, pelagic habitat in the Branisko succession of the Pieniny Klippen Basin and named it Cadosinopsis rehakovii sp. nov.
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