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Tectatodinium pellitum
Tectatodinium pellitum Wall, 1967, p.113, pl.16, figs.11–12. Emendation: Head, 1994a, p.308,310.
Taxonomic junior synonym: Tectatodinium grande, according to Head (1994a, p.308); Tectatodinium rugulatum, questionably according to Head (1994a, p.308), and according to Head and Nøhr-Hansen (1999, p.577).
Motile equivalent: Gonyaulax spinifera (Claparède and Lachmann, 1859) Diesing, 1866, according to Wall and Dale (1967, p.352; 1968c, p.270) and Dodge (1989, p.289).
Holotype: Wall, 1967, pl.16, fig.12
Locus typicus: 33¦ 34.5' N., 35¦ 12' E
Stratum typicum: Miocene-Holocene
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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.
Tectatodinium pellitum Wall, 1967, emend. Head, 1994a. Gonyaulacoideae, emended diagnosis from Head (1994a, p.308,310), cysts proximate and nearly spherical to slightly ovoid usually with a slight apical protuberance up to about 1.5 µm high. Wall comprises a pedium about 0.1 µm or less thick, and a much thicker spongy luxuria. The basal ca. 0.5 µm of the luxuria often appears vesicular in optical section. Exterior surface of the luxuria is open and has a roughened texture with occasional short, sinuous projecting fibrils. Archeopyle is precingular and formed by the loss of 3"; archeopyle margin often distinctly irregular, adcingular angles usually well-developed; no accessory sutures. Operculum monoplacoid and free. There are no other indications of tabulation. Size: holotype length 53 µm, width 49 µm, average wall thickness 3.5um. Labrador Sea specimens, maximum diameter 32-52 µm, wall thickness 1.8-4.9 µm.
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Original description: Wall, 1967, p. 113
The test is ovoid and thick-walled. The latter is double-layered, the inner being thin and homogeneous, the outer thicker and spongy; apparently it is formed by numerous, finely interwoven fibrils so that in optical section the focus is indistinct In surface view the test appears microgranular. There is a large, dorsal, trapezoidal archeopyle but no girdle or ventral sulcus.
Dimensions. Test 40-55 µm, wall thickness 3-7 µm. Numerous examples.
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Emended diagnosis: Head 1994, p. 310
Cysts proximate and nearly spherical to slightly ovoid usually with a slight apical protuberance up to about 1.5 µm high. Wall comprises a pedium about 0.1 µm or less thick, and a much thicker spongy luxuria. The basal ca. 0.5 µm of the luxuria often appears vesicular in optical section. Exterior surface of the luxuria is open and has a roughened texture with occasional short, sinuous projecting fibrils. Archeopyle is precingular and formed by loss of the third precingular paraplate; archeopyle margin often distinctly irregular, adcingular angles usually well-developed; no accessory sutures. Operculum monoplacoid and free.There are no other indications of paratabulation.
Dimensions:
Holotype: length 53 µm, width 49.0 µm, average wall thickness ca. 3.5 µm (uncompressed specimen). Southern England specimen (middle Eocene): length 54 µm, average wall thickness ca. 3.0 µm (flattened specimen). Eocene specimens from the Labrador Sea are moderately compressed. Lower or middle Eocene specimens (sample ODP 105-647A-65R-1, 117-121 cm) from the Labrador Sea: maximum diameter 32(38.0)52 µm, standard deviation 4.59 (21 measurements); wall thickness ca. 1.8(3.0)4.9 µm,standard deviation 0.777 (21 measurements). Lower Eocene specimens (samples ODP 105-647A-66R-1, 66-69 cm and 105-647A-66R-2, 29-33 cm) from the Labrador Sea: maximum diameter 36(39.2)461 µm, standard deviation 2.61 (23 measurements); wall thickness ca. 2.3(3.5)4.6 µm, standard deviation 0.762 (23 measurements). All further measurements are of relatively uncompressed specimens. Black Sea specimen: length 52 µm, width 46 µm, average wall thickness ca. 1.7 µm (excluding loose fibrils). Block Canyon specimen: length 45 µm, width 46 µm, wall thickness ca. 2.8 µm. Coralline Crag specimens: maximum diameter 38(44.2)51 µm, standard deviation 2.99 (33 measurements); wall thickness ca. 2.1 (3.2)4.0 µm, standard deviation 0.408 (38 measurements).
Discussion: Head 1994, p. 310
New observations included in the emended diagnosis are the presence of an apical protuberance, details of the luxuria including its basal sublayer, and the characteristically irregular archeopyle margin. All these features are present on the holotype and have been observed also on numerous other specimens. The spongy luxuria appears microgranulate throughout its thickness when focusing down through the surface of the wall in bright field microscopy. The pedium is seen only in optical section and appears as a dark line. Specimens examined in this study have a wall thickness varying from ca. 1.6 to 3.7 µm, excluding projecting fibrils, but the literature suggests even greater variation. For example, Bujak (1980, p. 88) reported a range in luxuria thickness of 1.5-2 µm but occasionally reaching 7 µm on specimens of varying wall thickness. The principal archeopyle suture is irregular especially along the apical margin. SEM analysis of Coralline Crag specimens (mid Pliocene; see also SEM illustration in Morzadec-Kerfourn 1979, pl. 35, figs. 18-20) confirms details of wall structure -- notably that the luxuria is spongy (it consists of interconnecting, irregular, perforate lamellae) and usually has a distinctive basal sublayer which is underlain by an extremely thin (0.1 µm or less thick), solid pedium.
The holotype (presumed Holocene, Mediterranean Sea) is uncompressed and well preserved, and is embedded in glycerine jelly as a single grain mount. It is slightly ovoid with a slight apical protuberance of about 1 µm high. Occasional sinuous fibrils up to 2.0230m long project from the surface. Adcingular angles of principal archeopyle suture are well developed. The operculum is free and has fallen within the cyst.
Other specimens examined are smaller than the holotype but otherwise similar. The Black Sea specimen is ovoid and has a 1.5 µm-high apical protuberance. The wall is somewhat thinner than usual and there are unusually numerous loose fibrils emanating from the surface (see also Turon and Londeix 1988, pl.4, figs. 1-3). The Coralline Crag specimens have a luxuria somewhat more compact than that of the holotype. Consequently in optical section the luxuria often appears to have a fine pattern of wavy or intersecting subtangential interference lines (Bujak 1980, pl. 22, fig. I; Fechner and Mohr 1988, pl. 3, figs. 10-14; Manum et al. 1989, pl. 20, fig. 4; and illustrations herein). This is an optical diffraction effect. A low apical protuberance was seen on several Coralline Crag specimens (e.g., Plate 4, fig. 5), although most were oriented unfavorably for evaluating its persistence. The Block Canyon specimen also has a rather dense luxuria. It too has a slight apical prominence.
Comparison: Head 1994, p. 312
Tectatodinium grande Williams et al. 1993 is here considered a taxonomic junior synonym of Tectatodinium pellitum. Williams et al. (1993) chose as the holotype of Tectatodinium grande a specimen illustrated as Tectatodinium sp. 2 in Manum et al. (1989, pl. 20, figs. 3, 4) from the upper Miocene of the Norwegian Sea. Manum et al. (1989) did not publish a description of this morphotype, but photomicrographs of their single illustrated specimen (subsequently the holotype of Tectatodinium grande) clearly show all critical details that confirm its identification as Tectatodinium pellitum; namely a thin pedium, a thick (3.0 3.5 µm) spongy luxuria, lP precingular archeopyle with well defined angles and irregular margins, and a slight apical protuberance.
The morphology of this specimen is best appreciated when the illustrations (Manum et al. 1989, pl. 20, figs. 3, 4) are rotated 95o clockwise so that the apex faces upwards in accordance with normal convection .
Tectatodinium pellitum apparently differs from Tectatodinium rugulatum (Hansen 1977) McMinn 1988, described from the Danian of Denmark (Hansen 1977), only in wall thickness: 1.6-3.7 µm for T. pellitum (this study; but up to about 7 µm in Bujak 1980) vs 4-5 µm for T. rugulatum (Hansen 1977). Details of an apical boss and precise nature of the archeopyle margins are unknown for T. rugulatum but published illustrations (Hansen 1977, fig. 20 H, J; Schioler and Wilson 1993, pl. 4, fig. 12) suggest either that T. pellitum and T. rugulatum are synonymous (T. pellitum having priority) or that T. rugulatum differs only in minor detail. These two species need to be compared with care: if they are synonymous, the stratigraphic range of T. pellitum then extends into the Danian.
A thick spongy luxuria and irregular archeopyle margin distinguish T. pellitum from the superficially similar but columellate/tegillate Habibacysta tectata. The extant cyst Bitectatodinium tepikiense Wilson 1973 has a luxuria consisting of lamellae which arise from thickened bases, and a 2P archeopyle -- although specimens missing just one opercular plate have been misidentified as pellitum (e.g. Morzadec-Kerfourn 1984, pl. 4, fig. 14).
Occurrence in eastern England: Mid Pliocene Coralline Crag (about 3.55-3.75 Ma), Rockhall Wood, Sutton, all eight samples from lithological Units A and B (Balson and Long in Gibbard and Zalasiewicz 1988, p. 66-71; Balson 1990). Two specimens figured as T. pellitum from the Ludham borehole (Wall and Dale 1968a, pl. 1, figs. 8, 9) are judged from the illustrations to be, respectively, Bitectatodinium tepikiense (with one opercular plate in place) and Habibacysta tectata.
Previous records: Head 1994, p. 312
The following records (see also synonymy) are based on well-documented material or verified by personal observation and arranged by ascending stratigraphic order. Lower Eocene of northern Germany (Fechner and Mohr 1988). Lower through upper Eocene of the Labrador Sea (Head and Norris 1989; present study). Middle Eocene through Oligocene of Alabama, U.S.A. (Edwards 1977). Upper Eocene of southeastern England (Bujak 1980). Upper Eocene to lower Miocene of Italy (Biffi and Manum 1988). Oligocene through middle Miocene of northwest Germany (Fechner 1990; Fechner and Appfel 1990). Lower through upper Miocene of the Norwegian Sea (Manum et al. 1989; Mudie 1989). Lower through upper Miocene of DSDP Site 408, northern North Atlantic (Engel 1992). Lower Miocene through lower Pliocene of the Bay of Biscay (Engel 1992). Middle and upper Miocene of Denmark (Piasecki 1980). Middle Miocene through Holocene of the Caribbean Sea (Wall 1967). Middle or upper Miocene through Pleistocene of the Gulf of Mexico (Wrenn and Kokinos 1986). Upper Miocene of Spain (Jan du Chene 1977). Pannonian (approximately upper Miocene) of Hungary (Suto-Szen-tai 1982, 1985). Lower Pliocene of Corfu, Greece (Fechner and Koch 1991). Lower through uppermost Pliocene of DSDP Site 603, western North Atlantic (Kolev et al. 1992). Quaternary of the Mediterranean Sea (Rossignol 1964; Morzadec-Kerfourn 1979; Turon and Londeix 1988; de Vernal et al. 1992). Presumed Holocene of the Mediterranean Sea (Wall 1967). In addition, T. pellitum has been reported from modern sediments of offshore eastern U.S.A. (Wall and Dale 1967, 1968b) and elsewhere in the Atlantic Ocean (distributions in Wall et al. 1977 and Harland 1983).
Stratigraphic range: Head 1994, p. 314
Tectatodinium pellitum is an extant cyst species (Wall and Dale 1967, 1968b). It has a confirmed range base of upper lower Eocene in the Labrador Sea, occurring within nannofossil zone NP13 (as Tectatodinium sp. 1 in Head and Norris 1989; identification revised in present study). Tectatodinium pellitum also occurs in lower Eocene deposits of northern Germany, these possibly being lower lower Eocene (Fechner and Mohr 1988). If Tectatodinium pellitum is synonymous with Tectatodinium rugulatum, a species reported from the Danian of Denmark (Hansen 1977) and Danian of the North Sea (Schi01er and Wilson 1993), this will extend the known range of Tectatodinium pellitum into the lower Paleocene.
Ecology: Head 1994, p. 314
T. pellitum has a south-temperate to sub-tropical distribution in the North Atlantic (Harland 1983). It seldom constitutes more than 10 percent of the cyst assemblage (a maximum abundance of 15.9% was recorded from a sample off Peru; Edwards and Andrle 1992) and maximum abundances occur where summer sea-surface temperatures are 21-25°C and winter sea-surface temperatures are 8-10°C (Edwards and Andrle 1992). It has a neritic to oceanic ecological distribution and has been reported from estuarine sediments (Wall et al. 1977).
Botanical affinity: Head 1994, p. 314
Incubation studies (Wall and Dale 1967, 1968b) have shown Tectatodinium pellitum to be one of several cyst taxa produced by the Gonyaulax spinifera (Claparede and Lachmann 1859) Diesing 1866 type. These other cyst taxa include Nematosphaeropsis lemniscata (as Nematosphaeropsis balcombiana in Wall and Dale 1968b), Bitectatodinium tepikiense (see Dale 1976), Ataxiodinium choane (as Planinosphaeridium membranaceum in Dale 1976), and several species of the genus Spiniferites. Such multiplicity of cyst morphotypes from a single thecate species is now generally accepted as evidence for the presence of a complex of species (e.g., Dodge 1989). It also indicates either that the Gonyaulax spinifera complex is the product of convergent evolution (with respect to thecal morphology) or that evolutionary pressures have in the past acted unequally on theca and cyst--the theca responding conservatively in terms of morphology relative to the cyst.
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Tectatodinium cf. pellitum of Schioler et al. 1997, p. 90
Figured in Schioler et al. 1997: Plate III, 9-11
Description: Small ovoid cyst with a relatively thick spongy microgranulate phragm (2.5-3.5 µm) seemingly consisting of one wall layer only. The archeopyle type is P(3) judged from the shape and location. The archeopyle has an irregular margin (Plate III, 9). No other paratabulation observed.
Discussion: The taxon resembles T. pellitum closely; but is smaller. Furthermore, we failed to see the pedium (innermost solid layer) and the apical protuberance described from the holotype by Head (1994, p. 310, pl. I, figs. 3-5, 8) on the specimens from the ENCI section. This could, however, be due to lack of microscope resolution and unfavourable orientation of our specimens.
Dimensions (in µm, 3 specimens measured): length, 27 (32) 36; width, 25 (28) 33.
Occurrence: Very rare below the Lava Horizon, absent above.
Taxonomic junior synonym: Tectatodinium grande, according to Head (1994a, p.308); Tectatodinium rugulatum, questionably according to Head (1994a, p.308), and according to Head and Nøhr-Hansen (1999, p.577).
Motile equivalent: Gonyaulax spinifera (Claparède and Lachmann, 1859) Diesing, 1866, according to Wall and Dale (1967, p.352; 1968c, p.270) and Dodge (1989, p.289).
Holotype: Wall, 1967, pl.16, fig.12
Locus typicus: 33¦ 34.5' N., 35¦ 12' E
Stratum typicum: Miocene-Holocene
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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.
Tectatodinium pellitum Wall, 1967, emend. Head, 1994a. Gonyaulacoideae, emended diagnosis from Head (1994a, p.308,310), cysts proximate and nearly spherical to slightly ovoid usually with a slight apical protuberance up to about 1.5 µm high. Wall comprises a pedium about 0.1 µm or less thick, and a much thicker spongy luxuria. The basal ca. 0.5 µm of the luxuria often appears vesicular in optical section. Exterior surface of the luxuria is open and has a roughened texture with occasional short, sinuous projecting fibrils. Archeopyle is precingular and formed by the loss of 3"; archeopyle margin often distinctly irregular, adcingular angles usually well-developed; no accessory sutures. Operculum monoplacoid and free. There are no other indications of tabulation. Size: holotype length 53 µm, width 49 µm, average wall thickness 3.5um. Labrador Sea specimens, maximum diameter 32-52 µm, wall thickness 1.8-4.9 µm.
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Original description: Wall, 1967, p. 113
The test is ovoid and thick-walled. The latter is double-layered, the inner being thin and homogeneous, the outer thicker and spongy; apparently it is formed by numerous, finely interwoven fibrils so that in optical section the focus is indistinct In surface view the test appears microgranular. There is a large, dorsal, trapezoidal archeopyle but no girdle or ventral sulcus.
Dimensions. Test 40-55 µm, wall thickness 3-7 µm. Numerous examples.
---------------------------------
Emended diagnosis: Head 1994, p. 310
Cysts proximate and nearly spherical to slightly ovoid usually with a slight apical protuberance up to about 1.5 µm high. Wall comprises a pedium about 0.1 µm or less thick, and a much thicker spongy luxuria. The basal ca. 0.5 µm of the luxuria often appears vesicular in optical section. Exterior surface of the luxuria is open and has a roughened texture with occasional short, sinuous projecting fibrils. Archeopyle is precingular and formed by loss of the third precingular paraplate; archeopyle margin often distinctly irregular, adcingular angles usually well-developed; no accessory sutures. Operculum monoplacoid and free.There are no other indications of paratabulation.
Dimensions:
Holotype: length 53 µm, width 49.0 µm, average wall thickness ca. 3.5 µm (uncompressed specimen). Southern England specimen (middle Eocene): length 54 µm, average wall thickness ca. 3.0 µm (flattened specimen). Eocene specimens from the Labrador Sea are moderately compressed. Lower or middle Eocene specimens (sample ODP 105-647A-65R-1, 117-121 cm) from the Labrador Sea: maximum diameter 32(38.0)52 µm, standard deviation 4.59 (21 measurements); wall thickness ca. 1.8(3.0)4.9 µm,standard deviation 0.777 (21 measurements). Lower Eocene specimens (samples ODP 105-647A-66R-1, 66-69 cm and 105-647A-66R-2, 29-33 cm) from the Labrador Sea: maximum diameter 36(39.2)461 µm, standard deviation 2.61 (23 measurements); wall thickness ca. 2.3(3.5)4.6 µm, standard deviation 0.762 (23 measurements). All further measurements are of relatively uncompressed specimens. Black Sea specimen: length 52 µm, width 46 µm, average wall thickness ca. 1.7 µm (excluding loose fibrils). Block Canyon specimen: length 45 µm, width 46 µm, wall thickness ca. 2.8 µm. Coralline Crag specimens: maximum diameter 38(44.2)51 µm, standard deviation 2.99 (33 measurements); wall thickness ca. 2.1 (3.2)4.0 µm, standard deviation 0.408 (38 measurements).
Discussion: Head 1994, p. 310
New observations included in the emended diagnosis are the presence of an apical protuberance, details of the luxuria including its basal sublayer, and the characteristically irregular archeopyle margin. All these features are present on the holotype and have been observed also on numerous other specimens. The spongy luxuria appears microgranulate throughout its thickness when focusing down through the surface of the wall in bright field microscopy. The pedium is seen only in optical section and appears as a dark line. Specimens examined in this study have a wall thickness varying from ca. 1.6 to 3.7 µm, excluding projecting fibrils, but the literature suggests even greater variation. For example, Bujak (1980, p. 88) reported a range in luxuria thickness of 1.5-2 µm but occasionally reaching 7 µm on specimens of varying wall thickness. The principal archeopyle suture is irregular especially along the apical margin. SEM analysis of Coralline Crag specimens (mid Pliocene; see also SEM illustration in Morzadec-Kerfourn 1979, pl. 35, figs. 18-20) confirms details of wall structure -- notably that the luxuria is spongy (it consists of interconnecting, irregular, perforate lamellae) and usually has a distinctive basal sublayer which is underlain by an extremely thin (0.1 µm or less thick), solid pedium.
The holotype (presumed Holocene, Mediterranean Sea) is uncompressed and well preserved, and is embedded in glycerine jelly as a single grain mount. It is slightly ovoid with a slight apical protuberance of about 1 µm high. Occasional sinuous fibrils up to 2.0230m long project from the surface. Adcingular angles of principal archeopyle suture are well developed. The operculum is free and has fallen within the cyst.
Other specimens examined are smaller than the holotype but otherwise similar. The Black Sea specimen is ovoid and has a 1.5 µm-high apical protuberance. The wall is somewhat thinner than usual and there are unusually numerous loose fibrils emanating from the surface (see also Turon and Londeix 1988, pl.4, figs. 1-3). The Coralline Crag specimens have a luxuria somewhat more compact than that of the holotype. Consequently in optical section the luxuria often appears to have a fine pattern of wavy or intersecting subtangential interference lines (Bujak 1980, pl. 22, fig. I; Fechner and Mohr 1988, pl. 3, figs. 10-14; Manum et al. 1989, pl. 20, fig. 4; and illustrations herein). This is an optical diffraction effect. A low apical protuberance was seen on several Coralline Crag specimens (e.g., Plate 4, fig. 5), although most were oriented unfavorably for evaluating its persistence. The Block Canyon specimen also has a rather dense luxuria. It too has a slight apical prominence.
Comparison: Head 1994, p. 312
Tectatodinium grande Williams et al. 1993 is here considered a taxonomic junior synonym of Tectatodinium pellitum. Williams et al. (1993) chose as the holotype of Tectatodinium grande a specimen illustrated as Tectatodinium sp. 2 in Manum et al. (1989, pl. 20, figs. 3, 4) from the upper Miocene of the Norwegian Sea. Manum et al. (1989) did not publish a description of this morphotype, but photomicrographs of their single illustrated specimen (subsequently the holotype of Tectatodinium grande) clearly show all critical details that confirm its identification as Tectatodinium pellitum; namely a thin pedium, a thick (3.0 3.5 µm) spongy luxuria, lP precingular archeopyle with well defined angles and irregular margins, and a slight apical protuberance.
The morphology of this specimen is best appreciated when the illustrations (Manum et al. 1989, pl. 20, figs. 3, 4) are rotated 95o clockwise so that the apex faces upwards in accordance with normal convection .
Tectatodinium pellitum apparently differs from Tectatodinium rugulatum (Hansen 1977) McMinn 1988, described from the Danian of Denmark (Hansen 1977), only in wall thickness: 1.6-3.7 µm for T. pellitum (this study; but up to about 7 µm in Bujak 1980) vs 4-5 µm for T. rugulatum (Hansen 1977). Details of an apical boss and precise nature of the archeopyle margins are unknown for T. rugulatum but published illustrations (Hansen 1977, fig. 20 H, J; Schioler and Wilson 1993, pl. 4, fig. 12) suggest either that T. pellitum and T. rugulatum are synonymous (T. pellitum having priority) or that T. rugulatum differs only in minor detail. These two species need to be compared with care: if they are synonymous, the stratigraphic range of T. pellitum then extends into the Danian.
A thick spongy luxuria and irregular archeopyle margin distinguish T. pellitum from the superficially similar but columellate/tegillate Habibacysta tectata. The extant cyst Bitectatodinium tepikiense Wilson 1973 has a luxuria consisting of lamellae which arise from thickened bases, and a 2P archeopyle -- although specimens missing just one opercular plate have been misidentified as pellitum (e.g. Morzadec-Kerfourn 1984, pl. 4, fig. 14).
Occurrence in eastern England: Mid Pliocene Coralline Crag (about 3.55-3.75 Ma), Rockhall Wood, Sutton, all eight samples from lithological Units A and B (Balson and Long in Gibbard and Zalasiewicz 1988, p. 66-71; Balson 1990). Two specimens figured as T. pellitum from the Ludham borehole (Wall and Dale 1968a, pl. 1, figs. 8, 9) are judged from the illustrations to be, respectively, Bitectatodinium tepikiense (with one opercular plate in place) and Habibacysta tectata.
Previous records: Head 1994, p. 312
The following records (see also synonymy) are based on well-documented material or verified by personal observation and arranged by ascending stratigraphic order. Lower Eocene of northern Germany (Fechner and Mohr 1988). Lower through upper Eocene of the Labrador Sea (Head and Norris 1989; present study). Middle Eocene through Oligocene of Alabama, U.S.A. (Edwards 1977). Upper Eocene of southeastern England (Bujak 1980). Upper Eocene to lower Miocene of Italy (Biffi and Manum 1988). Oligocene through middle Miocene of northwest Germany (Fechner 1990; Fechner and Appfel 1990). Lower through upper Miocene of the Norwegian Sea (Manum et al. 1989; Mudie 1989). Lower through upper Miocene of DSDP Site 408, northern North Atlantic (Engel 1992). Lower Miocene through lower Pliocene of the Bay of Biscay (Engel 1992). Middle and upper Miocene of Denmark (Piasecki 1980). Middle Miocene through Holocene of the Caribbean Sea (Wall 1967). Middle or upper Miocene through Pleistocene of the Gulf of Mexico (Wrenn and Kokinos 1986). Upper Miocene of Spain (Jan du Chene 1977). Pannonian (approximately upper Miocene) of Hungary (Suto-Szen-tai 1982, 1985). Lower Pliocene of Corfu, Greece (Fechner and Koch 1991). Lower through uppermost Pliocene of DSDP Site 603, western North Atlantic (Kolev et al. 1992). Quaternary of the Mediterranean Sea (Rossignol 1964; Morzadec-Kerfourn 1979; Turon and Londeix 1988; de Vernal et al. 1992). Presumed Holocene of the Mediterranean Sea (Wall 1967). In addition, T. pellitum has been reported from modern sediments of offshore eastern U.S.A. (Wall and Dale 1967, 1968b) and elsewhere in the Atlantic Ocean (distributions in Wall et al. 1977 and Harland 1983).
Stratigraphic range: Head 1994, p. 314
Tectatodinium pellitum is an extant cyst species (Wall and Dale 1967, 1968b). It has a confirmed range base of upper lower Eocene in the Labrador Sea, occurring within nannofossil zone NP13 (as Tectatodinium sp. 1 in Head and Norris 1989; identification revised in present study). Tectatodinium pellitum also occurs in lower Eocene deposits of northern Germany, these possibly being lower lower Eocene (Fechner and Mohr 1988). If Tectatodinium pellitum is synonymous with Tectatodinium rugulatum, a species reported from the Danian of Denmark (Hansen 1977) and Danian of the North Sea (Schi01er and Wilson 1993), this will extend the known range of Tectatodinium pellitum into the lower Paleocene.
Ecology: Head 1994, p. 314
T. pellitum has a south-temperate to sub-tropical distribution in the North Atlantic (Harland 1983). It seldom constitutes more than 10 percent of the cyst assemblage (a maximum abundance of 15.9% was recorded from a sample off Peru; Edwards and Andrle 1992) and maximum abundances occur where summer sea-surface temperatures are 21-25°C and winter sea-surface temperatures are 8-10°C (Edwards and Andrle 1992). It has a neritic to oceanic ecological distribution and has been reported from estuarine sediments (Wall et al. 1977).
Botanical affinity: Head 1994, p. 314
Incubation studies (Wall and Dale 1967, 1968b) have shown Tectatodinium pellitum to be one of several cyst taxa produced by the Gonyaulax spinifera (Claparede and Lachmann 1859) Diesing 1866 type. These other cyst taxa include Nematosphaeropsis lemniscata (as Nematosphaeropsis balcombiana in Wall and Dale 1968b), Bitectatodinium tepikiense (see Dale 1976), Ataxiodinium choane (as Planinosphaeridium membranaceum in Dale 1976), and several species of the genus Spiniferites. Such multiplicity of cyst morphotypes from a single thecate species is now generally accepted as evidence for the presence of a complex of species (e.g., Dodge 1989). It also indicates either that the Gonyaulax spinifera complex is the product of convergent evolution (with respect to thecal morphology) or that evolutionary pressures have in the past acted unequally on theca and cyst--the theca responding conservatively in terms of morphology relative to the cyst.
------------------------------------
Tectatodinium cf. pellitum of Schioler et al. 1997, p. 90
Figured in Schioler et al. 1997: Plate III, 9-11
Description: Small ovoid cyst with a relatively thick spongy microgranulate phragm (2.5-3.5 µm) seemingly consisting of one wall layer only. The archeopyle type is P(3) judged from the shape and location. The archeopyle has an irregular margin (Plate III, 9). No other paratabulation observed.
Discussion: The taxon resembles T. pellitum closely; but is smaller. Furthermore, we failed to see the pedium (innermost solid layer) and the apical protuberance described from the holotype by Head (1994, p. 310, pl. I, figs. 3-5, 8) on the specimens from the ENCI section. This could, however, be due to lack of microscope resolution and unfavourable orientation of our specimens.
Dimensions (in µm, 3 specimens measured): length, 27 (32) 36; width, 25 (28) 33.
Occurrence: Very rare below the Lava Horizon, absent above.