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Pseudospiniferites manumii
Pseudospiniferites manumii Lund, 2002, p.87–88, pl.1, figs.1–7. Emendation: Schiøler, 2005, p.30, as Spiniferites manumii.
NOW Spiniferites. Originally Pseudospiniferites, subsequently (and now) Spiniferites.
Holotype: Lund, 2002, pl.1, figs.1–2.
Age: early Oligocene.
Original description (Lund, 2002)
Derivation of name: The species is named after SvE1N B. MANUM, University of Oslo, who led the group (MANUM et al. 1989) which illustrated the species as Spiniferites sp.1 from the Norwegian Sea (locality A in Figure 1 ).
Diagnosis: A large species (central body more than 65 micron) of Pseudospiniferites n.gen. with long spines characterized by weak development of the continuation of the spine connecting crests on the spine shafts, which may result in nearly smooth spine shafts.
Holotype and type locality: Specimen in Plate 1, Figures 1 - 2 ("England Finder" coordinates: 046/3), sample R23, Bed 24, locality Rumst -Terhagen from the Belgian Rupelian (Early Oligocene) type area. The holotype is deposited in Niedersiichsisches Landesamt fur Bodenforschung, Hanover.
Dimensions: Holotype: central body 85 microns, spines max. 48 microns long. Layer 24 in Kruibeke and Rumst-Terhagen Quarries (six specimens): central body 85- 120 (mean 99) microns, spines 40-48 (mean 43) microns. Well " B" (Figure.1) sample " XX30m" (30 specimens): central body 68- 90 (mean 77) microns, spines 30-48 (mean
. 36) microns.
Description: Large central body with two types of sculpture: (a) a low (micro)granulate-reticulate sculpture and (b) a higher sculpture with long, mainly gonal spines connected by low, often indistinct sutural ridges, which continue up the shafts of the spines where they may be hardly visible. The archaeopyle primarily includes the dorsal precingular plate, but primarily sutures radiating from plate break-up, so that the "archaeopyle" appears to include more plates, and even sutures at a dorsal hypocyst plate may break up.
Remarks:The sculpture of the central body wall varies from minute microreticulate-microgranulate (Plate 1, Figures 1, 2, 4, 7) to more rough reticulate to granulate (Plate 1, Figures 3, 5, 6). It is worth noting that this variation in sculpture occurs both in Belgian and Danish North Sea material, suggesting that it is not valuable for a taxon
differentiation. As noted under the remarks concerning the genus, the break-up around the archaeopyle might involve a varying number of sutures. Plate 1, Figure 4 is an example of extreme degree of break-up. The other extreme with minimal break-up is exhibited in Plate 1, Figure 6 here and by MANUM et al. (1989, Plate 17, Figure 5), where it is doubtful if any sutures radiating from the archaeopyle break up at all. The strong variation of the "archaeopyle" is unusual within one species or even within one genus of dinoflagellate cysts. However, the other distinctive characters (size, long gonal spines, and sculptured central body) of Pseudospiniferites manumii observed in many specimens in the same sample indicate that these belong to one population/species. The variation of the "archaeopyle" is therefore not considered to be useful for taxon differentiation in this particular case.
Emended diagnosis (Schioler, 2005):
Large skolochorate, spiniferate, gonyaulacoid cyst with smooth, slender and usually flexuous to sinuous processes and a conspicuous closely spaced vermiculate surface ornament.
Emended description (Schioler, 2005):
Large, skolochorate, spiniferate, gonyaulacoid cyst. The processes are gonal, simple and branch distally in a trifid manner, and are smooth, slender and usually flexuous to sinuous. The cyst body is ornamented heavily with closely spaced vermiculae (width of vermiculae: 1–3 µm). Low parasutural crests connect the processes proximally. The crests are embedded in the surface ornament and only discernible under high magnification appearing as low, straight structures connecting the process bases. The archaeopyle is precingular, type P3´´. The paratabulation is sexiform gonyaulacoid: 3’, 5–6’’, 6c, 5’’, 1p, 1’’’’, ?s, shown by parasutural ridges and gonal processes. ‘
Stratigraphical range. Uppermost Bartonian to lower Rupelian in Alma-1X. In Alma-1X, the FDO of the taxon is recorded at the same stratigraphic level as that observed by Lund (2002), Manum et al. (1989) and Williams & Manum (1999), i.e. in the lower Rupelian, below the FDO of Enneadocysta pectiniformis and above the FDO of Areosphaeridium diktyoplokum. Its occurrence pattern thus confirms the observation that the species constitutes an important intra-Rupelian stratigraphic marker (Lund, 2002).
Remarks. The prime reason for Lund (2002) establishing the new genus Pseudospiniferites was the ‘tendency towards suture break-up around the primary single plate precingular archeopyle’. However, Lund also stated that these accessory archaeopyle sutures occur only sporadically in a cyst population (Lund, 2002, p. 87). Three of his illustrated specimens are, indeed, ruptured cysts (Lund, 2002, pl. 1, figs 1, 2, 4, 7), one is a fragment (Lund, 2002, pl. 1, fig. 3) and two (Lund, 2002, pl. 1, figs 5, 6) are intact. The taxon is well known from North Sea boreholes, occuring in various states of preservation. The population encountered in Alma-1X occurs at the same stratigraphical level as the specimens described by Lund and is dominated by well-preserved specimens that do not show signs of accessory archaeopyle sutures. The specimens figured by Manum et al. (1989) from ODP Site 643 and by Williams & Manum (1999) from ODP Site 908 – both Norwegian Sea – are intact and also lack accessory archaeopyle sutures. Therefore, the character stressed as a criterion for establishing a new genus is believed to be a preservation artefact. The generic diagnosis of the genus Pseudospiniferites also includes the presence of granulate to (micro) reticulate surface ornament (Lund, 2002, p. 87). However, the emended diagnosis of the genus Spiniferites allows for such surface ornament (Sarjeant, 1970, p. 75) and several recognized species have an ornamented surface. The specimens observed from Alma-1X, those figured by Manum et al. (1989), Williams & Manum (1999) and illustrated by Lund (2002; figs 5, 6) from the North Sea all have at least some flexuous processes. Although most processes on the holotype are straight, some are flexuous (Lund, 2002, pl. 1, figs 1, 2). As all the specimens mentioned above are undoubtedly conspecific, the description of the taxon is widened to allow for specimens with flexuous processes. The species is transferred to Spiniferites Mantell, 1850 as a species of that genus characterized by its large size, conspicuous closely spaced vermiculate ornament and the presence of flexuous to sinuous processes.
NOW Spiniferites. Originally Pseudospiniferites, subsequently (and now) Spiniferites.
Holotype: Lund, 2002, pl.1, figs.1–2.
Age: early Oligocene.
Original description (Lund, 2002)
Derivation of name: The species is named after SvE1N B. MANUM, University of Oslo, who led the group (MANUM et al. 1989) which illustrated the species as Spiniferites sp.1 from the Norwegian Sea (locality A in Figure 1 ).
Diagnosis: A large species (central body more than 65 micron) of Pseudospiniferites n.gen. with long spines characterized by weak development of the continuation of the spine connecting crests on the spine shafts, which may result in nearly smooth spine shafts.
Holotype and type locality: Specimen in Plate 1, Figures 1 - 2 ("England Finder" coordinates: 046/3), sample R23, Bed 24, locality Rumst -Terhagen from the Belgian Rupelian (Early Oligocene) type area. The holotype is deposited in Niedersiichsisches Landesamt fur Bodenforschung, Hanover.
Dimensions: Holotype: central body 85 microns, spines max. 48 microns long. Layer 24 in Kruibeke and Rumst-Terhagen Quarries (six specimens): central body 85- 120 (mean 99) microns, spines 40-48 (mean 43) microns. Well " B" (Figure.1) sample " XX30m" (30 specimens): central body 68- 90 (mean 77) microns, spines 30-48 (mean
. 36) microns.
Description: Large central body with two types of sculpture: (a) a low (micro)granulate-reticulate sculpture and (b) a higher sculpture with long, mainly gonal spines connected by low, often indistinct sutural ridges, which continue up the shafts of the spines where they may be hardly visible. The archaeopyle primarily includes the dorsal precingular plate, but primarily sutures radiating from plate break-up, so that the "archaeopyle" appears to include more plates, and even sutures at a dorsal hypocyst plate may break up.
Remarks:The sculpture of the central body wall varies from minute microreticulate-microgranulate (Plate 1, Figures 1, 2, 4, 7) to more rough reticulate to granulate (Plate 1, Figures 3, 5, 6). It is worth noting that this variation in sculpture occurs both in Belgian and Danish North Sea material, suggesting that it is not valuable for a taxon
differentiation. As noted under the remarks concerning the genus, the break-up around the archaeopyle might involve a varying number of sutures. Plate 1, Figure 4 is an example of extreme degree of break-up. The other extreme with minimal break-up is exhibited in Plate 1, Figure 6 here and by MANUM et al. (1989, Plate 17, Figure 5), where it is doubtful if any sutures radiating from the archaeopyle break up at all. The strong variation of the "archaeopyle" is unusual within one species or even within one genus of dinoflagellate cysts. However, the other distinctive characters (size, long gonal spines, and sculptured central body) of Pseudospiniferites manumii observed in many specimens in the same sample indicate that these belong to one population/species. The variation of the "archaeopyle" is therefore not considered to be useful for taxon differentiation in this particular case.
Emended diagnosis (Schioler, 2005):
Large skolochorate, spiniferate, gonyaulacoid cyst with smooth, slender and usually flexuous to sinuous processes and a conspicuous closely spaced vermiculate surface ornament.
Emended description (Schioler, 2005):
Large, skolochorate, spiniferate, gonyaulacoid cyst. The processes are gonal, simple and branch distally in a trifid manner, and are smooth, slender and usually flexuous to sinuous. The cyst body is ornamented heavily with closely spaced vermiculae (width of vermiculae: 1–3 µm). Low parasutural crests connect the processes proximally. The crests are embedded in the surface ornament and only discernible under high magnification appearing as low, straight structures connecting the process bases. The archaeopyle is precingular, type P3´´. The paratabulation is sexiform gonyaulacoid: 3’, 5–6’’, 6c, 5’’, 1p, 1’’’’, ?s, shown by parasutural ridges and gonal processes. ‘
Stratigraphical range. Uppermost Bartonian to lower Rupelian in Alma-1X. In Alma-1X, the FDO of the taxon is recorded at the same stratigraphic level as that observed by Lund (2002), Manum et al. (1989) and Williams & Manum (1999), i.e. in the lower Rupelian, below the FDO of Enneadocysta pectiniformis and above the FDO of Areosphaeridium diktyoplokum. Its occurrence pattern thus confirms the observation that the species constitutes an important intra-Rupelian stratigraphic marker (Lund, 2002).
Remarks. The prime reason for Lund (2002) establishing the new genus Pseudospiniferites was the ‘tendency towards suture break-up around the primary single plate precingular archeopyle’. However, Lund also stated that these accessory archaeopyle sutures occur only sporadically in a cyst population (Lund, 2002, p. 87). Three of his illustrated specimens are, indeed, ruptured cysts (Lund, 2002, pl. 1, figs 1, 2, 4, 7), one is a fragment (Lund, 2002, pl. 1, fig. 3) and two (Lund, 2002, pl. 1, figs 5, 6) are intact. The taxon is well known from North Sea boreholes, occuring in various states of preservation. The population encountered in Alma-1X occurs at the same stratigraphical level as the specimens described by Lund and is dominated by well-preserved specimens that do not show signs of accessory archaeopyle sutures. The specimens figured by Manum et al. (1989) from ODP Site 643 and by Williams & Manum (1999) from ODP Site 908 – both Norwegian Sea – are intact and also lack accessory archaeopyle sutures. Therefore, the character stressed as a criterion for establishing a new genus is believed to be a preservation artefact. The generic diagnosis of the genus Pseudospiniferites also includes the presence of granulate to (micro) reticulate surface ornament (Lund, 2002, p. 87). However, the emended diagnosis of the genus Spiniferites allows for such surface ornament (Sarjeant, 1970, p. 75) and several recognized species have an ornamented surface. The specimens observed from Alma-1X, those figured by Manum et al. (1989), Williams & Manum (1999) and illustrated by Lund (2002; figs 5, 6) from the North Sea all have at least some flexuous processes. Although most processes on the holotype are straight, some are flexuous (Lund, 2002, pl. 1, figs 1, 2). As all the specimens mentioned above are undoubtedly conspecific, the description of the taxon is widened to allow for specimens with flexuous processes. The species is transferred to Spiniferites Mantell, 1850 as a species of that genus characterized by its large size, conspicuous closely spaced vermiculate ornament and the presence of flexuous to sinuous processes.