The Cenozoic gonyaulacacean dinoflagellate genera Operculodinium Wall, 1967 and Protoceratium Bergh, 1881 and their phylogenetic relationships

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doi: 10.1666/12-103
Author(s): Paez-Reyes, Manuel; Head, Martin J.
Author Affiliation(s): Primary:
Brock University, Department of Earth Sciences, St. Catharines, ON, Canada
Volume Title: Journal of Paleontology
Source: Journal of Paleontology, 87(5), p.786-803. Publisher: Paleontological Society, Lawrence, KS, United States. ISSN: 0022-3360 CODEN: JPALAZ
Note: In English. 94 refs.; illus., incl. 4 plates, sketch map
Summary: To clarify the systematic positions of the important gonyaulacacean genera Operculodinium Wall, 1967 emend. Matsuoka et al., 1997 and Protoceratium Bergh, 1881, we present in detail the tabulation of the Oligocene-Pleistocene, thermophilic, cyst-defined species Operculodinium bahamense Head in Head and Westphal, 1999 emend., and the extant, cosmopolitan, theca-defined species Protoceratium reticulatum (Claparede and Lachmann, 1859) Butschli, 1885. Both species have a sexiform hyposomal tabulation, and L-type (Protoceratium reticulatum) or modified L-type (Operculodinium bahamense) ventral organization. Protoceratium reticulatum has dextral torsion of the hypotheca, requiring assignation of the genus to the subfamily Cribroperidinioideae Fensome et al., 1993, whereas Operculodinium bahamense has neutral torsion requiring assignation to the subfamily Leptodinioideae Fensome et al., 1993. The stratigraphic range of this subfamily is now extended upwards to the lower Pleistocene. Paradoxically, Protoceratium reticulatum produces a cyst whose morphology is circumscribed by the cyst-defined genus Operculodinium, either implying polyphyletic origins for this genus or that combinations of ventral organization and torsion used to subdivide the family Gonyaulacaceae cannot always be applied rigidly. In detail, Operculodinium bahamense is shown to have an unusual ventral tabulation in which the first apical plate contacts the apical pore complex but not the sulcus. The new term "episert" is proposed to describe this plate relationship, which appears to have evolved independently in several lineages of the suborder Gonyaulacineae.
Year of Publication: 2013
Research Program: ODP Ocean Drilling Program
Key Words: 09 Paleontology, Paleobotany; Atlantic Ocean; Cenozoic; Dinoflagellata; Great Bahama Bank; Leg 166; Living taxa; Microfossils; Miocene; Morphology; Neogene; North Atlantic; ODP Site 1007; Ocean Drilling Program; Oligocene; Paleogene; Palynomorphs; Phylogeny; Pleistocene; Pliocene; Protoceratium reticulatum; Quaternary; SEM data; Taxonomy; Tertiary
Coordinates: N243016 N243016 W0791921 W0791921
Record ID: 2013078136
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Abstract, Copyright, The Paleontological Society, Reference includes data from GeoScienceWorld, Alexandria, VA, United States