A morphological comparison of two cladopyxidacean dinoflagellates: the extant Micracanthodinium setiferum and the fossil Cladopyxidium saeptum (Dinophyceae, Gonyaulacales)
Mertens, K.N.; Carbonell-Moore, M.C.; Gardner, K. (2022). A morphological comparison of two cladopyxidacean dinoflagellates: the extant Micracanthodinium setiferum and the fossil Cladopyxidium saeptum (Dinophyceae, Gonyaulacales). Palynology 46(1): 1-17. https://dx.doi.org/10.1080/01916122.2021.1934908
In: Palynology. American Association of Stratigraphic Palynologists: Austin, Tex. etc.. ISSN 0191-6122; e-ISSN 1558-9188, more
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| Keywords |
Micracanthodinium setiferum (Lohmann) Deflandre, 1937 [WoRMS]
Marine/Coastal |
| Author keywords |
dinoflagellates; partiform; Kofoidian; porichnion; Paleocene; Eocene |
| Authors | | Top |
- Mertens, K.N., more
- Carbonell-Moore, M.C.
- Gardner, K.
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| Abstract |
Among dinoflagellates, extant cladopyxidaceans may provide a missing link to better understand the first evolutionary transformations from ancestral configurations toward the more abundant and more derived patterns in Gonyaulacales and Peridiniales. A restudy of the extant, motile-defined Micracanthodinium setiferum using plankton samples from the Indian and Atlantic oceans and the Mediterranean Sea demonstrates that the correct plate formula is Po, Pt, X, 3′ + *4′, 4a, 7′′, 7C, 4S, ?6′′′, 0p, 2′′′′. A ventral pore is found between 1′, 3′ and *4′. A restudy of the extinct, fossil-defined Cladopyxidium saeptum from the upper Paleocene of Delaware (USA), demonstrated the presence of an identical tabulation. A ventral pore (= porichnion) was positioned between *1′ and 7′′. Cladopyxidium is morphologically closer to Micracanthodinium than to Cladopyxis. Since Cladopyxidium has been extinct since the middle Eocene, it is unlikely that Micracanthodinium and Cladopyxidium have a direct biological link; the close morphological similarity between them does, however, suggest an important phylogenetic relationship between them in the evolution of cladopyxidaceans. |
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