title: Phylogeny of calcareous dinoflagellates as inferred from ITS and ribosomal sequence data.
abstract: 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.
authors.affiliation: Freie Universität Berlin, Fachbereich Geologische Wissenschaften-Fachrichtung Paläontologie, Malteserstrasse 74-100, D-122 49 Berlin, Germany. caix@zedat.fu-berlin.de
authors.forename: Marc
authors.initials: M
authors.lastname: Gottschling
authors.forename: Helmut
authors.initials: H
authors.lastname: Keupp
authors.forename: Jörg
authors.initials: J
authors.lastname: Plötner
authors.forename: Ronny
authors.initials: R
authors.lastname: Knop
authors.forename: Helmut
authors.initials: H
authors.lastname: Willems
authors.forename: Monika
authors.initials: M
authors.lastname: Kirsch
mesh_terms: D000818:Animals; D001483:Base Sequence; D021903:DNA, Ribosomal Spacer / Q000235:genetics*; D004141:Dinoflagellida / Q000145:classification* / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics*; D016415:Sequence Alignment
chemical_list: D021903:DNA, Ribosomal Spacer; D012340:RNA, Ribosomal, 5.8S