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Amphorula metaelliptica
Amphorula metaelliptica, Dodekova, 1969; Emendation: Monteil, 1990
Holotype: Dodekova, 1969, pl.4, figs.1-6, text-figs.E-F
Locus typicus:
Stratum typicum: Thitonian
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Original description: [Dodekova 1969, p. 20]:
Description:
Body ellipsoidal or spherical, with a thin wall. Devided into separate, semi-elliptical fields, regularly arranged and opened in equatorial direction. Arrangement of the fields, their dimensions and habit correspond entirely to the tabulation of dinoflagellate cysts.
The tabulation scheme of Amphorula metaelliptica is 4'?, 6'', 6s.t., 6''', 1p, 1ppl, 1''''. Six long and narrow fields make out the equatorial girdle or transversal furrow. Every field contains at its margins a distally slender or branched appendices. Ventrally, the fields have different levels just like the margins of the transversal furrow with certain plate forms. The epitheca has 6 semi-elliptical pre-equatorial fields, of which 1'' and 6'' are relatively smaller. Between 1'' and 6'' there is a narrow and sharp-angled field, that marks the position of the longitudinal furrow. The construction of the apex is unknown, it is likely, that it consists of four fields (?). The hypotheca has six posterior fields. 1''' is very small, analogous to the tabulation of Gonyaulax. The others have a semi-elliptical form. 2''' and 6''' are smaller and almost alike. 1p has a round transverse section, 1ppl is well built. The antapex is occupied by a field of a round or rectangular projection. All fields on the epi- or hypotheca are fenced by fan-shaped appendices that open towards the transversal furrow. The appendices have united or dentated and perforated extremities. The length of the appendices varies from 10 to 26 µm. Only 1p and 1'''' have tubular appendices. The membrane of the body has fine edges, pronounced around the fields, that pass over the appendices. The archaeopyle is apical. All specimens have an archaeopyle and because of that the construction of the apex has not been determined. The aperture has a zig-zag contour. The separation of the apex diminishes the resistance of the cysts. The membrane of the epitheca is often torn into separate trapezoid plates, each one having a semi-elliptical field with an appendice. (Description based on 46 specimens).
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Emended description:
Monteil, 1990, p. 603:
Description:
Proximochorate-septate (kledo chorate) cyst with subspherical body. Apparently two layered acavate cyst; periphragm and endophragm appressed except where septa are formed. No parasutural features. Septa high. slightly to strongly flaring, intratabular arcuate semi-elliptical to semicircular. Adcingular septa open, arcuate, semi elliptical to semicircular, rounded Septa striated, entire, penforated or scalloped-penforated. Distal extremity smooth or denticulate.
Archeopyle apical, type (4A), with angular margin; parasulcal notch marked; operculum free.
Paratabulation indicated by archeopyle and septa; gonyaulacacean, inferred formula: 1 or 2 pr, 4', 0a, 6'', 6c, 6''', 1 p, 1''''. 5s
Paracingulum indicated by six rectilinear septa, each with one slender distally bifurcate process, at both extremities. Five parasulcal paraplates indicated by four septa: as septum triangular closed, ps septum heel-shaped closed, ras and rs fused in a single rectilinear longitudinal septum. Is septum rectilinear longitudinal, possibly fused with 1''''. The ventral organization is of the L-type.
Dimensions:
Holotype range
largest diameter 63µm
smallest diameter 52µm
length of septa 11µm 10-26µm
Affinities:
A metaelllptica differs from A. dodekovae in having open adcingular septa rather than closed ones. A metaelllptica differs from A dellcata in having entire. perforated or scalloped-perforated septa rather than an appearance of a delicate complex of processes.
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Poulsen, 1996, p. 65:
Remarks:
Both Zotto et al. (1987) and Monteil (1990) stated that this species has arcuate rather than annulate pre- and postcingular septa, but Polish specimens possess both types of septa.
Recorded occurrences:
Denmark: Scriniodinium crystallinum Zone, Subzone d - Glossodinium dimorphum Zone, Subzone e.
Poland: Hypselocyclum-Scythicus Zones.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Amphorula metaelliptica Dodekova, 1969, emend. Monteil, 1990. According to Monteil (1990, p. 603), this is a proximochorate-septate (kledochorate) cyst with subspherical body. Apparently two-layered acavate cyst; periphragm and endophragm appressed except where septa are formed. No parasutural features. Septa high, slightly to strongly flaring, intratabular arcuate semi-elliptical to semicircular. Adcingular septa open, arcuate, semi-elliptical to semicircular, rounded. Septa striated, entire, perforated or scalloped-perforated. Distal extremity smooth or denticulate. Archeopyle apical type (4A), with angular margin; sulcal notch marked; operculum free. Paratabulation indicated by archeopyle and septa; gonyaulacacean, inferred formula: 1 or 2 pr, 4', 0a, 6", 6c, 6"’, 1p, 1"”, 5s. Cingulum indicated by six rectilinear septa, each with one slender, distally bifurcate process, at both extremities. Five sulcal paraplates indicated by four septa: as septum triangular closed, ps septum heel-shaped closed, ras and rs fused in a single rectilinear longitudinal septum, ls septum rectilinear longitudinal possibly fused with 1“”. The ventral organization is of the L-type. Monteil (1990) stated that A.metaelliptica differs from A.dodekovae in having open adcingular septa rather than closed ones and from A.delicata in having entire, perforated or scalloped-perforated septa rather than an appearance of a delicate “complex of processes”.
Size (from Dodekova, 1969), largest diameter 63 µm, smallest diameter 52 µm, length of septa 10-26 µm. Berriasian stratotype specimens (from Monteil, 1990), overall length 50-75 µm, overall width 55-72 µm, length of septa 6-12 µm.
Holotype: Dodekova, 1969, pl.4, figs.1-6, text-figs.E-F
Locus typicus:
Stratum typicum: Thitonian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Dodekova 1969, p. 20]:
Description:
Body ellipsoidal or spherical, with a thin wall. Devided into separate, semi-elliptical fields, regularly arranged and opened in equatorial direction. Arrangement of the fields, their dimensions and habit correspond entirely to the tabulation of dinoflagellate cysts.
The tabulation scheme of Amphorula metaelliptica is 4'?, 6'', 6s.t., 6''', 1p, 1ppl, 1''''. Six long and narrow fields make out the equatorial girdle or transversal furrow. Every field contains at its margins a distally slender or branched appendices. Ventrally, the fields have different levels just like the margins of the transversal furrow with certain plate forms. The epitheca has 6 semi-elliptical pre-equatorial fields, of which 1'' and 6'' are relatively smaller. Between 1'' and 6'' there is a narrow and sharp-angled field, that marks the position of the longitudinal furrow. The construction of the apex is unknown, it is likely, that it consists of four fields (?). The hypotheca has six posterior fields. 1''' is very small, analogous to the tabulation of Gonyaulax. The others have a semi-elliptical form. 2''' and 6''' are smaller and almost alike. 1p has a round transverse section, 1ppl is well built. The antapex is occupied by a field of a round or rectangular projection. All fields on the epi- or hypotheca are fenced by fan-shaped appendices that open towards the transversal furrow. The appendices have united or dentated and perforated extremities. The length of the appendices varies from 10 to 26 µm. Only 1p and 1'''' have tubular appendices. The membrane of the body has fine edges, pronounced around the fields, that pass over the appendices. The archaeopyle is apical. All specimens have an archaeopyle and because of that the construction of the apex has not been determined. The aperture has a zig-zag contour. The separation of the apex diminishes the resistance of the cysts. The membrane of the epitheca is often torn into separate trapezoid plates, each one having a semi-elliptical field with an appendice. (Description based on 46 specimens).
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Emended description:
Monteil, 1990, p. 603:
Description:
Proximochorate-septate (kledo chorate) cyst with subspherical body. Apparently two layered acavate cyst; periphragm and endophragm appressed except where septa are formed. No parasutural features. Septa high. slightly to strongly flaring, intratabular arcuate semi-elliptical to semicircular. Adcingular septa open, arcuate, semi elliptical to semicircular, rounded Septa striated, entire, penforated or scalloped-penforated. Distal extremity smooth or denticulate.
Archeopyle apical, type (4A), with angular margin; parasulcal notch marked; operculum free.
Paratabulation indicated by archeopyle and septa; gonyaulacacean, inferred formula: 1 or 2 pr, 4', 0a, 6'', 6c, 6''', 1 p, 1''''. 5s
Paracingulum indicated by six rectilinear septa, each with one slender distally bifurcate process, at both extremities. Five parasulcal paraplates indicated by four septa: as septum triangular closed, ps septum heel-shaped closed, ras and rs fused in a single rectilinear longitudinal septum. Is septum rectilinear longitudinal, possibly fused with 1''''. The ventral organization is of the L-type.
Dimensions:
Holotype range
largest diameter 63µm
smallest diameter 52µm
length of septa 11µm 10-26µm
Affinities:
A metaelllptica differs from A. dodekovae in having open adcingular septa rather than closed ones. A metaelllptica differs from A dellcata in having entire. perforated or scalloped-perforated septa rather than an appearance of a delicate complex of processes.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Poulsen, 1996, p. 65:
Remarks:
Both Zotto et al. (1987) and Monteil (1990) stated that this species has arcuate rather than annulate pre- and postcingular septa, but Polish specimens possess both types of septa.
Recorded occurrences:
Denmark: Scriniodinium crystallinum Zone, Subzone d - Glossodinium dimorphum Zone, Subzone e.
Poland: Hypselocyclum-Scythicus Zones.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Amphorula metaelliptica Dodekova, 1969, emend. Monteil, 1990. According to Monteil (1990, p. 603), this is a proximochorate-septate (kledochorate) cyst with subspherical body. Apparently two-layered acavate cyst; periphragm and endophragm appressed except where septa are formed. No parasutural features. Septa high, slightly to strongly flaring, intratabular arcuate semi-elliptical to semicircular. Adcingular septa open, arcuate, semi-elliptical to semicircular, rounded. Septa striated, entire, perforated or scalloped-perforated. Distal extremity smooth or denticulate. Archeopyle apical type (4A), with angular margin; sulcal notch marked; operculum free. Paratabulation indicated by archeopyle and septa; gonyaulacacean, inferred formula: 1 or 2 pr, 4', 0a, 6", 6c, 6"’, 1p, 1"”, 5s. Cingulum indicated by six rectilinear septa, each with one slender, distally bifurcate process, at both extremities. Five sulcal paraplates indicated by four septa: as septum triangular closed, ps septum heel-shaped closed, ras and rs fused in a single rectilinear longitudinal septum, ls septum rectilinear longitudinal possibly fused with 1“”. The ventral organization is of the L-type. Monteil (1990) stated that A.metaelliptica differs from A.dodekovae in having open adcingular septa rather than closed ones and from A.delicata in having entire, perforated or scalloped-perforated septa rather than an appearance of a delicate “complex of processes”.
Size (from Dodekova, 1969), largest diameter 63 µm, smallest diameter 52 µm, length of septa 10-26 µm. Berriasian stratotype specimens (from Monteil, 1990), overall length 50-75 µm, overall width 55-72 µm, length of septa 6-12 µm.