Back
Andalusiella spinosa
Andalusiella spinosa, Guler et al., 2005 (p. 420–421, figs.4A–O.)
Holotype: Guler et al., 2005, figs.4I–J.
Paratype: Slide UNSLP 3431-2 31.5/107.2, England Finder: J31 4; Figs. 4.I-J.
Type locality: Estancia 25 de Mayo, Cerro Calafate, south of the Lago Argentino, Austral Basin.
Type horizon: Sample VG16, 260 m above the base of the section; late Maastrichtian.
Stratigraphic occurence: Frequent at sample GV16.
Age: late Maastrichtian.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Guler et al., 2005]:
Diagnosis:
Proximate, acrocavate dinoflagellate cyst with a rhomboidal central body, long apical and left antapical horns. Periphragm densely covered by fine spines. Parasulcus with flagellar scar. Assumed peridinioid paratabulation indicated only by the cingulum and archeopyle.
Description:
Proximate cyst with a rhomboidal to ovoidal central body. One long apical horn, and one well-developed left antapical horn with an incipient right antapical horn, indicated by a poorly developed bulge. The apical horn is longer than the longest antapical horn.
Wall composed of a smooth endophragm and a delicate periphragm bearing fine spines, densely distributed, up to 2 µm in length. Endophragm extends almost up to the tip of the horns, typical of strongly acrocavate cysts. A few specimens show thickenings of the endophragm at the base of the apical horn (epistomia).
The assumed peridinioid paratabulation is reflected by the archeopyle, cingulum and occasionally by incomplete sutural features.
Cingulum slightly offset, indicated by two parallel crests. The sulcus has a bean-shaped flagellar scar.
The archeopyle is intercalary type I/I, standard 2a hexa, isodeltaform, with a generally adherent operculum.
Dimensions:
Overall length: 75 (84) 110 µm; central body length: 40 (48) 55 µm, width: 38 (43.5) 52 µm; length of apical horn: 13 (24) 40 µm; length of left antapical horn: 8 (13) 20 µm (20 specimens measured).
Affinities/Comparison:
Andalusiella spinosa differs from other species of Andalusiella in having a periphragm covered by fine spines. According to the original diagnosis of Andalusiella (Svalbardella) rhomboides by Boltenhagen (1977) the periphragm is completely covered by micro-spines. However, according to the emendation of Masure et al . (1996) the wall is described being composed of a verrucose periphragm and endophragm. Moreover A. rhomboides is slightly acrocavate to cornucavate which distinguishes it from A. spinosa sp. nov. which is strongly acrocavate.
Holotype: Guler et al., 2005, figs.4I–J.
Paratype: Slide UNSLP 3431-2 31.5/107.2, England Finder: J31 4; Figs. 4.I-J.
Type locality: Estancia 25 de Mayo, Cerro Calafate, south of the Lago Argentino, Austral Basin.
Type horizon: Sample VG16, 260 m above the base of the section; late Maastrichtian.
Stratigraphic occurence: Frequent at sample GV16.
Age: late Maastrichtian.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Guler et al., 2005]:
Diagnosis:
Proximate, acrocavate dinoflagellate cyst with a rhomboidal central body, long apical and left antapical horns. Periphragm densely covered by fine spines. Parasulcus with flagellar scar. Assumed peridinioid paratabulation indicated only by the cingulum and archeopyle.
Description:
Proximate cyst with a rhomboidal to ovoidal central body. One long apical horn, and one well-developed left antapical horn with an incipient right antapical horn, indicated by a poorly developed bulge. The apical horn is longer than the longest antapical horn.
Wall composed of a smooth endophragm and a delicate periphragm bearing fine spines, densely distributed, up to 2 µm in length. Endophragm extends almost up to the tip of the horns, typical of strongly acrocavate cysts. A few specimens show thickenings of the endophragm at the base of the apical horn (epistomia).
The assumed peridinioid paratabulation is reflected by the archeopyle, cingulum and occasionally by incomplete sutural features.
Cingulum slightly offset, indicated by two parallel crests. The sulcus has a bean-shaped flagellar scar.
The archeopyle is intercalary type I/I, standard 2a hexa, isodeltaform, with a generally adherent operculum.
Dimensions:
Overall length: 75 (84) 110 µm; central body length: 40 (48) 55 µm, width: 38 (43.5) 52 µm; length of apical horn: 13 (24) 40 µm; length of left antapical horn: 8 (13) 20 µm (20 specimens measured).
Affinities/Comparison:
Andalusiella spinosa differs from other species of Andalusiella in having a periphragm covered by fine spines. According to the original diagnosis of Andalusiella (Svalbardella) rhomboides by Boltenhagen (1977) the periphragm is completely covered by micro-spines. However, according to the emendation of Masure et al . (1996) the wall is described being composed of a verrucose periphragm and endophragm. Moreover A. rhomboides is slightly acrocavate to cornucavate which distinguishes it from A. spinosa sp. nov. which is strongly acrocavate.