A morphological comparison of two cladopyxidacean dinoflagellates: the extant Micracanthodinium setiferum and the fossil Cladopyxidinium saeptum (Dinophyceae, Gonyaulacales)
|Author(s)||Mertens Kenneth1, Carbonell-Moore M. Consuelo2, Gardner Kristina3|
|Affiliation(s)||1 : Ifremer, LITTORAL, F-29900 Concarneau, France
2 : Oregon State University, Department of Botany and Plant Pathology, College of Agricultural Sciences, 2082 Cordley Hall, Corvallis, OR 97331-2902, U.S.A.
3 : Department of Earth Sciences, University of Delaware, DGS Building, 257 Academy Street Newark, DE 19716-7501, U.S.A
|Source||Palynology (0191-6122) (Informa UK Limited), 2022-01 , Vol. 46 , N. 1 , P. 1934908 (17p.)|
|WOS© Times Cited||3|
|Keyword(s)||dinoflagellates, partiform, Kofoidian, porichnion, Paleocene, Eocene|
Among dinoflagellates, extant cladopyxidaceans may provide a missing link to better understand the first evolutionary transformations from ancestral configurations towards the more abundant and more derived patterns in Gonyaulacales and Peridiniales. A restudy of the extant, motile-defined Micracanthodinium setiferum from plankton samples from the Indian and Atlantic Oceans and 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 (U.S.A), 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. However, since Cladopyxidium has been extinct since the middle Eocene it is unlikely that Micracanthodinium and Cladopyxidium will have a direct biological link; the close morphological link between both does suggest an important phylogenetic relationship between both in the evolution of cladopyxidaceans.