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Lasagniella herngreenii
Lasagniella herngreenii Brinkhuis et al., 2000, p.101,103, pl.1, figs.1-13; pl.2, figs.1-12; pl.3, figs.1-12; pl.6, figs.1-2; pl.7, fig.1.
Holotype: Brinkhuis et al., 2000, pl.1, figs.11-13.
Age: latest Maastrichtian-Danian.
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Lasagniella herngreenii Brinkhuis et al., in press, has four to eight wall layers, commonly seven to eight, which vary in shape from a subspherical innermost wall to a rhomboidal outermost wall. There is an apical protrusion up to 5 µm high. The individual columellate walls also bear verrucae, tubercles or clavate projections which do not touch the next layer outwards. The outermost wall is continuous, undulating with a rugulate aspect. The archeopyle when fully developed is of type A3I3P, resulting from the loss of 3', 1-3a, 3-5" plates, however, some specimens lose fewer plates, the simplest involving 2a only. In some specimens, the third and or fifth precingular plates may remain attached. Occasional specimens appear complete, without any visible archeopyle. Size: length 37-61 µm, width 24-65 µm.
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Original description (Brinkhuis et al., 2000):
Lasagniella herngreenii sp. Nov. (Plate I, 1-13; Plate II, 1-12; Plate III, 1-12; Plate VI, 1; Plate VII, 1.
Synonymy
1986 Xenicodinium rugulatum auct. Non Hansen 1977, Herngreen et al., Plate XII, 6
Diagnosis: A species of Lasagniella with an outermost wall layer that is undulating and regulate.
Description: the four to eight, commonly seven to eight, wall layers of L. herngreenii vary in shape from a subspherical innermost wall to a rhomboidal outermost wall. This variation results from increasing separation of the walls away from the cingulum, leading to development of and apical protuberance up to 5 µm high. The individual columellate walls also bear verrucae, tubercles or clavate projections which do not touch the next layer outwards. The outermost wall is continuous undulating, with a regulate aspect (Plates VI, 1; Plate VII, 1). The archeopyle, when fully developed, is of type A3I3P, resulting from the loss of the 3’, 1a-3a, and 3’’-5’’ paraplates; however, some specimens lose fewer paraplates, the simplest involving 2a only. In some specimen, the third and/or fifth precingular paraplates may remain attached without any visible archeopyle.
Dimensions: Holotype length 45 µm, width 42 µm. range of 17 specimens: length 37-61 µm, width 24-65 µm.
Statigraphic occurrence: Latest Maastrichtian and Danian, 106.25-30m, Bunde Borehole, South Limburg, The Netherlands. Rare (samples Bunde 46-1 MID, 40 MID, 35-2 MID, 31-2 MID, 27-2 MID, 26-2 BASE, 26-2 MID, 26-2 TOP, 26-1 BASE, 26-1 MID, 26-1 TOP, 23-1 MID, 17-2 TOP).
Remarks: Lasagniella herngreenii occurs in deposits thought to be marginal marine, judging from the high concentrations of Paralecaniella indentata.
Holotype: Brinkhuis et al., 2000, pl.1, figs.11-13.
Age: latest Maastrichtian-Danian.
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Lasagniella herngreenii Brinkhuis et al., in press, has four to eight wall layers, commonly seven to eight, which vary in shape from a subspherical innermost wall to a rhomboidal outermost wall. There is an apical protrusion up to 5 µm high. The individual columellate walls also bear verrucae, tubercles or clavate projections which do not touch the next layer outwards. The outermost wall is continuous, undulating with a rugulate aspect. The archeopyle when fully developed is of type A3I3P, resulting from the loss of 3', 1-3a, 3-5" plates, however, some specimens lose fewer plates, the simplest involving 2a only. In some specimens, the third and or fifth precingular plates may remain attached. Occasional specimens appear complete, without any visible archeopyle. Size: length 37-61 µm, width 24-65 µm.
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Original description (Brinkhuis et al., 2000):
Lasagniella herngreenii sp. Nov. (Plate I, 1-13; Plate II, 1-12; Plate III, 1-12; Plate VI, 1; Plate VII, 1.
Synonymy
1986 Xenicodinium rugulatum auct. Non Hansen 1977, Herngreen et al., Plate XII, 6
Diagnosis: A species of Lasagniella with an outermost wall layer that is undulating and regulate.
Description: the four to eight, commonly seven to eight, wall layers of L. herngreenii vary in shape from a subspherical innermost wall to a rhomboidal outermost wall. This variation results from increasing separation of the walls away from the cingulum, leading to development of and apical protuberance up to 5 µm high. The individual columellate walls also bear verrucae, tubercles or clavate projections which do not touch the next layer outwards. The outermost wall is continuous undulating, with a regulate aspect (Plates VI, 1; Plate VII, 1). The archeopyle, when fully developed, is of type A3I3P, resulting from the loss of the 3’, 1a-3a, and 3’’-5’’ paraplates; however, some specimens lose fewer paraplates, the simplest involving 2a only. In some specimen, the third and/or fifth precingular paraplates may remain attached without any visible archeopyle.
Dimensions: Holotype length 45 µm, width 42 µm. range of 17 specimens: length 37-61 µm, width 24-65 µm.
Statigraphic occurrence: Latest Maastrichtian and Danian, 106.25-30m, Bunde Borehole, South Limburg, The Netherlands. Rare (samples Bunde 46-1 MID, 40 MID, 35-2 MID, 31-2 MID, 27-2 MID, 26-2 BASE, 26-2 MID, 26-2 TOP, 26-1 BASE, 26-1 MID, 26-1 TOP, 23-1 MID, 17-2 TOP).
Remarks: Lasagniella herngreenii occurs in deposits thought to be marginal marine, judging from the high concentrations of Paralecaniella indentata.