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Dissiliodinium lichenoides
Dissiliodinium lichenoides Feist-Burkhardt and Monteil, 2001, p.75-76, fig.5, nos.1-3; fig.6c; fig.17, nos.1-4; table 2 (part).
Holotype: Feist-Burkhardt and Monteil, 2001, fig.5, nos.1-2; fig.17, no.4.
Age: Late Aalenian-Early Bajocian.
Derivation of name: The specific epithet, lichenoides, is derived from the Greek leichen (=lichen) in reference to the cyst’s ornamentation.
Description: Cyst proximate, subspherical. Autophargm thin, ornamented by small, regular rounded to angular, or irregular elements whose variable size and density determines scabrate to strongly granular areas, grouped in lichen-like clusters in the more ornamented zones. Archeopyle precingular, compound, variable, formed by the loss of up to 5 precingular paraplates (1’’-5’’), opercular pieces free, adherent partially detached or adherent in place. Paratabulation generally indicated only by archeopyle when precingular paraplates are separated of displaced. Ocasionally narrow lines, drawn by the lack or ornamentation or alignments of granules can locally indicate parasutures. Apical paraplates remain attached to the hypocyst by an isthmus consisting off the paraplates 6’’, as, and, most foten 1’’. Paraplates of the apical cap are sometimes partially differentiated. The apical cap outline indicated the presence of four apical and one dorsal anterior intercalary paraplates. Epicystal paratabulation gonyaulacacean, partial paratabulation formula: ?2pr, 4’, 1a, 6’’, as. Precinguar paraplates of unequal size and stalked except for 3’’; paraplate 2’’ is extremely elongate, 1’’ is reduced and subtriangular. Boundary 1’’/2’ very short giving to the paraplate 1’’ its typical shape.Paracingulum usually not expresses, sometimes indicated by parallel transverse structures, laevorotatory. Parasulcus generally not marked, may be indicated by a faint depression and a reduction in ornamentation.
Dimensions: Holotype: 86 µm wide at the paracingulum in lateral view (compressed specimen in glycerine jelly slide); range in glycerie jelly slides: 73-90 µm wide at the paracingulum in lateral view (partly compresses specimens), in SEM: 54-65 µm (partially compresses specimens).
Comparison: D. lichenoides n. sp. differs from D. globulus Drugg 1978 and D. willei Bailey & Partington 1990 in the type or ornamentation and in having a dorsal anterior intercalary paraplate )see Tab. 2).
Stratigraphical and geographical occurrence: Feist-Burkhardt (1990): SW-Germany, Upper Aalenian, upper Murchisonae Zone to Early Bajocian, Laeviuscula Zone. Burkhalter et al. (1997): Switzerland, Upper Aalenian – Lower Bojocian.
Holotype: Feist-Burkhardt and Monteil, 2001, fig.5, nos.1-2; fig.17, no.4.
Age: Late Aalenian-Early Bajocian.
Derivation of name: The specific epithet, lichenoides, is derived from the Greek leichen (=lichen) in reference to the cyst’s ornamentation.
Description: Cyst proximate, subspherical. Autophargm thin, ornamented by small, regular rounded to angular, or irregular elements whose variable size and density determines scabrate to strongly granular areas, grouped in lichen-like clusters in the more ornamented zones. Archeopyle precingular, compound, variable, formed by the loss of up to 5 precingular paraplates (1’’-5’’), opercular pieces free, adherent partially detached or adherent in place. Paratabulation generally indicated only by archeopyle when precingular paraplates are separated of displaced. Ocasionally narrow lines, drawn by the lack or ornamentation or alignments of granules can locally indicate parasutures. Apical paraplates remain attached to the hypocyst by an isthmus consisting off the paraplates 6’’, as, and, most foten 1’’. Paraplates of the apical cap are sometimes partially differentiated. The apical cap outline indicated the presence of four apical and one dorsal anterior intercalary paraplates. Epicystal paratabulation gonyaulacacean, partial paratabulation formula: ?2pr, 4’, 1a, 6’’, as. Precinguar paraplates of unequal size and stalked except for 3’’; paraplate 2’’ is extremely elongate, 1’’ is reduced and subtriangular. Boundary 1’’/2’ very short giving to the paraplate 1’’ its typical shape.Paracingulum usually not expresses, sometimes indicated by parallel transverse structures, laevorotatory. Parasulcus generally not marked, may be indicated by a faint depression and a reduction in ornamentation.
Dimensions: Holotype: 86 µm wide at the paracingulum in lateral view (compressed specimen in glycerine jelly slide); range in glycerie jelly slides: 73-90 µm wide at the paracingulum in lateral view (partly compresses specimens), in SEM: 54-65 µm (partially compresses specimens).
Comparison: D. lichenoides n. sp. differs from D. globulus Drugg 1978 and D. willei Bailey & Partington 1990 in the type or ornamentation and in having a dorsal anterior intercalary paraplate )see Tab. 2).
Stratigraphical and geographical occurrence: Feist-Burkhardt (1990): SW-Germany, Upper Aalenian, upper Murchisonae Zone to Early Bajocian, Laeviuscula Zone. Burkhalter et al. (1997): Switzerland, Upper Aalenian – Lower Bojocian.