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Three new dinoflagellate cysts from the Moroccan Paleocene-Eocene phosphates
Review of Palaeobotany and Palynology, 70 (1992): 325-338
325
Elsevier Science Publishers B.V., Amsterdam
Three new dinoflagellate cysts from the Moroccan PaleoceneEocene phosphates M a r i e - J o Soncini Universitb Louis Pasteur, Institut de Gdologie, 1 Rue Blessig, 67084 Strasbourg Cedex, France (Received July 9, 1991; revised and accepted October l I, 1991)
ABSTRACT Soncini, M.-J., 1992. Three new dinoflagellatecysts from the Moroccan Paleocene-Eocene phosphates. Rev. Palaeobot.
Palynol., 70: 325-338. Moroccan phosphate deposits from the Phosphate Plateau (Oulad Abdoun basin, near Khouribga)contain varied and well preserved dinoflagellate cysts. Among them, a new genus: Bitubericysta and three new species: B. boroujiana, Liesbergia abdounensis and Spinidinium stellatum are described in this paper. The two gonyaulacoidcysts have been found in Upper Paleocene (Thanetian) and Lower Eocene (Ypresian) sediments, the peridinioid cyst has been observed in Upper Paleocene (Thanetian) and basal Eocene (basal Ypresian) material.
Introduction The new dinoflagellate cysts presented in this paper belong to a rich and varied dinocysts flora recently studied (Soncini, 1990). As the organic matter lacks maturity in Moroccan phosphates in the Oulad Abdoun basin (Benalioulhaj, 1989), the dinocysts also present in this material lack both stiffness and colouration but they are well preserved (Soncini and Rauscher, 1988; Rauscher et al., 1990). This is not the case with calcareous nannofossils and foraminifera which have not been studied. Pollen grains are rare, hardly reaching 2% of the total palynomorph content in 2 levels out of a hundred. Age assignments then are strictly based on dinocysts (Soncini, 1990). The three new species of dinocysts described here, one of which belongs to a new genus, have been observed in the upper part of the two boreholes under study: SB !9 and $4 (Fig. l). Spinidinium stellatum is typically present in Thanetian levels and at the Thanetian/Ypresian boundary (Figs.2, 3). Liesbergia abdounensis has been observed in both Thanetian and Ypresian levels 0034-6667/92/$05.00
(Figs.2, 3) and Bitubericysta boroufiana is restricted to lower Ypresian levels (Fig.2). There is no possibility of finding the two gonyaulacoid cysts higher in the phosphatic lithological series of SB 19 borehole (Eocene ?) as the material has been oxidized and washed out by meteoritic waters. Comprehensive lithological, sedimentary, geochemical descriptions of the Maastrichtian-Paleocene-Eocene phosphatic series in the Oulad Abdoun can be found in Belfkira (1980; borehole SB 19, among others) and in Benalioulhaj (1989; borehole $4, among others). Holotypes, paratypes and other figured specimens of the three species described are housed in the palynological slide collection of the Laboratoire de Palyno!ogie, Centre de G6ochimie de la Surface, Strasbourg, France. All photographs are made with a Vario Orthomat system on a Leitz Ortholux II microscope, using interferential contrast.
Systematic palynology Division PYRROPHYTA Pascher 1914 Class DINOPHYCEAEFritsch 1935
© 1992-- ElsevierSciencePublishers B.V. All rights reserved
326
M.-J. SONCINi
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Fig.3. Stratigraphy and lithology of SB 19 borehole (Oulad Abdoun, Morocco) and stratigraphic range of Liesbergia abdounensis and Sp#ffdinium stellatum.
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Genus Bitubericysta gen. nov.
Diagnosis: Cyst spheroidal, skolochorate, twolayered. Thin endophragm closely appressed to fibro-pitted periphragm variable in thickness. Intra-tabular processes well-developed, arising from the periphragm only, indicating a complete gonyaulacacean paratabulation, with a Danea-type organization. Small apical protrusion broad and solid. Processes fibrous and hollow, simple buccinate to complexely divided, expanding distally and irregularly recurving in a spinous margin. Annular to soleate antapical complex, surrounding a solid periphragmal protrusion variable in length. Archeopyle type P (4), operculum h'ee.
Type species: Bitubericysta boroujiana gen. nov. et
Bitubericysta boroujiana sp. nov.
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Fig.2. Stratigraphy and lithology of $4 borehole (Oulad Abdoun, Morocco) and stratigraphic range of Bitubericysta boroujiana, Liesbergia abdounensis and Spinidinium stellatum.
Order
PERIDINIALES
Haeckel 1894
sp. nov.
Holotype: Plate I, 1-3. Palynological sample and Derivation of name: Bitubericysta: from bi-tuber (latin), two protrusions, for apical and antapical features
slide 14409-1, level 45, Borehole $4, Oulad Abdoun, Morocco. England Finder references: U 35.
327
THREE NEW DINOFLAGELLATE CYSTS FROM MOROCCO
Paratype: Plate I, 9-1 I. Palynological sample and slide 14409-1, level 45, Borehole $4, Oulad Abdoun, Morocco. England Finder references: S-T 37. Derivation of name: boroufiana: in reference to Al Borouj, near Khouribga, in the vicinity of the borehole Type locality: Ai Borouj, Oulad Abdoun Phosphate Basin, Morocco Stratigraphic horizon: Ypresian, Borehole $4, level 45 Relative abundance: abundant (17%) Diagnosis: Spheroidal, skolochorate, two-layered cyst. Thin endophragm closely appressed to fibropitted pedphragm variable in thickness. Processes well developed, hollow and fibrous, arising from periphragm only; simple buccinate (precingular and II, Ill, VI postcingular) to complexely divided (IV and V postcingular), distally expanding and recurving in an irregular spinous margin. One process per paraplate, reflecting a complete gonyaulacacean paratabulation with a Danea-type organization. Paracingular processes tubular to latispinous, simple or divided, parasulcai ones simple and slender. Bifurcate or trifurcate apical protrusion, short, broad and solid, made by periphragm only. Annular to soleate antapical complex surrounding a solid periphragmal protrusion variable in length. Archeopyle type P (4), operculum free. Dimensions: holotype maximum diameter: 123.5 l~m, maximum processus length: 39.5 l~m, antapical protrusion: 14 ~tm; range maximum diameter: 103-(126)-152 l~m, maximum processus length: 32.5(41)-54 l~m, antapical protrusion: 7-(13)- 18.5 om; periphragm thickness (without polar protrusion and process): 2.5-5.5 ~tm; endophragm thickness: 1.5-2 ~tm; 15 specimens measured. Description: Bitubericysta cysts are typically spheroidal. The polar features are very distinctive but variab!e. The apical protrusion is solid and exclusively periphragmal: endocoele is not involved in this feature and less than 1% of the population show the endophragm slightly protruding into one or both polar projections; it is bifid or trifid,
massive, and typically linked to the proximal part of the process from apical paraplate B (Plate I, 3-6, Plate II, l). The antapical pole is also highly distinctive by the periphragmal protrusion, shorter than processes but variable in length (7 to 18.5 llm), commonly with a rounded tip, associated with a soleate complex of long and loosely fibrous projections, more or less linked laterally and distally (Plate I, 2, 7, 8, 10). This complex is open on ventral side (Plate I, 2, 10). Other processes are clearly intratabular, tubular, hollow, open distally. In paracingular area, processes are tubular or slightly flattened to latispinous on dorsal side (Plate I, 3), i.e. they are elliptical in cross-section, perpendicularly to the polar axis. They are simple, distally expanded in a paintbrush-like fashion. They can also be divided more or less close to their proximal part (bifurcate, trifurcate, complex...), particularly on dorsal side, but they clearly reflect 6 paracingular paraplates (Fig.4). In parasulcal area, l i, ai, fu, li, Ira, Iu, X and Z processes are discernible (Plate I, l, I l). Processes are hollow, slender and buccinate, with a spinous slightly recurved margin, densely fibrous, only lu possibly showing distal branching. Process of paraplate// is also smaller than pre- and postcingulars and can be incorporated in a parasulcai group in which processes depict faint alignments as follows: li and ai equal medium size, parallel to paracingulum organization; fu, Iu, II in a growing size order, not parallel to paracingulum but bending towards antapical pole; Ii, Ira, X in a growing size order, t
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Fig.4. Paratabulation pattern (Taylor-Evitt notation) of Bitubericysta boroujiana gen. et sp. nov. interpreted from processes distribution. Each process is represented by its proximal section. (a) external view of dorsal side. (b) external view of ventral side.
III
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329
THREE NEW DINOFLAGELLATE CYSTS FROM MOROCCO
in a diagonal arrangement; and Z slightly offset on the right side, below the large process of postcingular paraplate VI (Fig.4). Apical and precingular processes are larger (A and li smaller than B and C, 2 and 5 smaller than 3 and 6), densely to loosely fibrous, sometimes fenestrate. They are commonly simple tubular, largely expanded distally in paintbrush-like fashion. Distal margin is irregularly recurved and spinous. Postcingulars are comparable to precingulars on ventral side (Ill, VI) but larger, proximally tubular, more or less divided and largely expanded distally. On dorsal side (IV, V), processes are complexely divided, proximally arranged in an arcuate to soleate feature, opened towards the apex (Plate I, 3, 9). The plate boundary between IV and V complexes is then situated in a middorsal position, facing the archeopyle (Fig.4). Comparisons: At first sight, Bitubericysta is similar to Cordosphaeridium (Eisenack) Davey 1969: spheroidal shape, fibro-pitted to fibrous periphragm, intratabular position of processes reflecting a gonyaulacacean paratabulation pattern. Global aspect of processes compares well with C. exilimurum Davey and Williams in Davey et al. 1966. However, solid, periphragmal projections have never been described by authors on Cordosphaeridium: "not distinctive" apical and antapical processes are depicted by Davey (1969), or a slightly distinctive
antapical process (longer) is mentioned by Sarjeant (1981). In fact, there are always small to great differences (polar features for example) between Bitubericysta and the few other fibrous dinocysts which seem to show some morphological resemblance with it (Table l): Amphorosphaeridium Davey 1969 or Fibrocysta Stover and Evitt 1978, for example. As regards the paraplates organization, Bitubericysta proves close affinities with Danea (Morgenroth) Drugg, 1970, in spite of important morphological differences between the two genera (penitabular or intratabular septa frequent to dominant among projections on Danea dinocysts for example). As there are also morphological differences between Bitubericysta and the other "Danea-type'" dinocysts (Damassa, 1984) like Turbiosphaera Archangelsky 1969 (Table l), Bitubericysta will, perhaps, be considered as a new member of the Danea-group (Damassa, 1984)? Genus Liesbe~'gia Berger 1986
Type species: Liesbergia liesbergensis Berger 1986 Early Oxfordian, Liesberg Dorf, Berner Jura, Switzerland. Liesbergia abdounensis sp. nov. Holotype: Plate II, 4-6. Palynological sample and slide 14404-1, level 51, Borehole $4, Oulad
PLATE !
Bitubericysta boroujiana gen. et sp. nov. Bar-scale 20 p.m for all photographs = x 300, except 4 and 8: bar-scale l0 prn -- × 450. 1-3. Holotype. I. External view/ventral side, slide 14409-1, England Finder references U 35, borehole $4, level 45. 2. Medium locus/ventral side, same coordinates. 3. Internal view/dorsal side, same coordinates. Note the soleate processes complex on IV postcingular paraplate and the latispinous paracingular processes. 4. Medium focus, slide 14409-1, E.F. ref. L 50-1, borehole $4, level 45. Detail of preapical "process-protrusion' linked to apical process of paraplate B. Note the fenestration of B. 5. External view/dorsal side, slide 14409-1, E.F. ref H 34-2, borehole $4, level 45. Clear focus on apical C process and central tip of preapical "process-protrusion". 6. Lower focus, same coordinates. Clear focus on apical B process and lateral tip of preapical "process-protrusion'. Note the link between B and the apical protrusion. 7. Focus series from external view/dorsal side to optical section, slide 14409-1, E.F. ref. H 34-2, borehole $4, level 45. 8. Detail of antapical organization of projections (protrusion and pr,~cesses), slide 14409-1, E.F. ref. L 40-3, borehole $4, level 45. 9-11. Paratype. 9. Internal view/dorsal side, slide 14409-1, E.F. ref. S-T 37, borehole $4, level 45. Note the soleate processes complex on IV and V postcingular parapiates. 10. External view/ventral side, same coordinates. Note the antapical protrusion. I I. Higher focus/ventral side, same coordinates.
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331
THREE NEW DINOFLAGELLATE CYSTS FROM MOROCCO
TABLE 1 Comparison of diagnostic features of Bitubericysta gen. nov. with morphologically similar fibrous genera (archeopyle type ! P) Bitubericysta
Cordosphaeridium
Turbiosphaera
Amphorosphaeridium
Fibrocysta
spheroidal
ovoidal
ovoidal
periphragm + endophragm 1 antapical 1 apical
periphragm + endophragm none
periphragm + endophragm none
spheroidal to ovoidal periphragm + endophragm none
tabular l/paraplate buccinate, expanded + branched distally, hollow distinct
tabular l/paraplate buccinate, expanded + branched distally, solid or hollow distinct
tabular l/paraplate wide and flat to membranous
strictly non tabular or occasional tabular tubiform, spinous distally, hollow
non tabular
undistinct
undistinct
no yes
no yes (slightly)
distinct to partially problematical yes yes
yes yes (usually)
yes yes (sometimes)
CENTRAL BODY Shape spheroidal layers polar protrusion(s) PROCESSES distribution shape and structure
paratabulation
distinctive apical distinctive antapical
Abdout~, X 54.
Morocco.
England
F i n d e r references:
Paratype 1: Plate II, 2, 3. Palynological sample a n d slide 14404-1, level 51, Borehole $4, O u l a d A b d o u n , M o r o c c o . E n g l a n d F i n d e r references: O 54-3. Paratype 2: Plate II, 7, 8. Palynological sample
autophragm ! apical + ! antapical
slightly expanded or branched distally
and slide 14404-1, level 51, B o r e h o l e $4, O u l a d A b d o u n , M o r o c c o . E n g l a n d F i n d e r references: U 51-4. Derivation o f name: abdounensis: in reference to the O u l a d A b d o u n P h o s p h a t e Basin ( M o r o c c o ) Type locality: A! Borouj, O u l a d A b d o u n p h o s p h a t e basin, M o r o c c o
PLATE II Bar-scale 20 I~m= x 500.
I. Bitubericystaboroufianagen. et sp. nov. External view/right lateral side, slide 14409-1, England Finder references P 42, borehole $4, level 45.
2-9 Liesbergia abdounensissp. nov. 2, 3. Paratype 1. 2. Internal view/right lateral side, slide 14404-I, E.F. ref. O 54-3, borehole $4, level 51. Note the low relief of parasutures. 3. Medium focus, same coordinates. Note the elongation of periphragm projections building the apical horn. 4-6 Holotype 4. External view/left lateral side, slide 14404-1, E.F. ref. X 54, borehole $4, level 51. 5. Lower focus (partially external, partially internal or optical section), same coordinates. Note the apical elongation and intrication of projections building the apical horn. 6. Internal view/right lateral side, same coordinates. 7, 8. Paratype 2. 7. External view/ventral area, slide 14404-1, E.F. ref. U 51-4, borehole $4, level 51. Note the 6/A/li parasutures contacts and lu/2 parasuture contact. 8. Internal view/mid-dorsal-left lateral side, same coordinates. Note the apical elongation and intrication of projections building the apical horn. 9. Internal view/dorsal side, slide 14404-I, E.F. ref. Y 48-2, borehole $4, level 51. Paracingulum area broken under the archeopyle. Note the relation between projections and inner part of autophragm surface.
332
Stratigraphic horizon: Thanetian, Borehole SB 19, level 65, Ypresian, Borehole $4, levels 51, 49, 46 Relative abundance: rare in each level Diagnosis: Proximate, acavate, subspherical to subpolygonal cyst. Prominent truncated apical horn, broad-based, consisting of anastomosed trabeculae. External surface of autophragm covered by a dense pilate or clavate ornamentation, with occasional distal connections. Basal part of autophragm generally slightly protruding into the apical trabecular structure. Complete paratabulation underlined by ridges of distally linked projections, higher than intratabular ornamentation. Gonyaulacoid sexiform, Gonyaulacysta-type arrangement of paraplates. Distinctive topology of ventral area: A contacts ai, li narrow, roughly triangular, not in contact with lu, A larger than lu. Archeopyle P(4), operculum free. Dimensions: holotype maximum length: 104.5 lam, maximum widt'l: 81 ~tm, apical horr.: 14 lam; range maximum length including apical horn: 70-105 ~tm (89 lxm), maximum width: 60-85 ~tm (71 ~tm), maximum length of apical horn, between wall and tip of projections: 7-19 ~tm (12.5 ~tm); thickness of wall including surface's ornamentation: 2-4 lxm; parasutural ridges: 4.5-5.5 ~tm; 15 specimens measured. Description: Moroccan cysts described here are proximate, acavate, subspherical to subpolygonal in outline; the hypocyst is rounded, and the epicyst is subconical (Plate II, 2). The prominent apical horn is variable in length, with a broad basis and a truncated tip. It consists exclusively of anastomosing "trabeculae, coming from the elongated elements of ornamentation (Fig.5). Autophragm bears a dense ornamentation on external surface (Plate II, 9), formed by short projections with rounded tips, that can be simple, bifurcate, and sometimes distally linked (Fig.5), drawing an irregular reticulate and granulate patterning in high focus observation. No continuous external layer can be delimited. The basal part of the autophragm generally shows a small protrusion into the apical
M.-J. SONCINI
Fig.5. Sketch drawing of the apical horn of Liesbergia
abdounensis sp. nov.
anastomosed trabeculae structure (variable character) (Plate II, 9). A narrow paracingulum is delimited by two ridges formed by anastomosing and/or distally linked projections. The parasulcus is slightly hollow, with an ornamentation of lower relief. Archeopyle is of type P(4), the operculum is free. All the parasutures are underlined by ridges of irregular height, higher than intratabular ornamentation (Plate II, 2, 4-8) and composed of distally linked projections. Paratabulation is Gonyaulacoid, of Gonyaulacysta-type (Fig.6). The apical area has not been observed; A/lu, B/C, C/A parasutures all disappear in the apical trabeculate network of the horn (Plate II, 9). There is a 6-sided central antapical paraplate Y (sexiform), probably in symmetrical arrangement (cf. text-fig. 2, Helenes, 1986). The ventral area seems to show a sigmoidal sulcus: S-type organization (Evitt, 1985). The arrangement of paraplates on ventral epicyst is hardly discernible (Plate II, 7), but 1i is evidently narrow, roughly triangular-shaped and clearly not in contact with lu. Consequently, A contacts ai: A/ai arrangement (Helenes, 1986). A is larger than lu, and there is no obliteration of their parasuture, li, Im, lu are not distinct. Complete paratabulation of precingular, paracingular and postcingular areas have been observed (Fig.6). Comparison: At first sight, the moroccan dinocysts described could be assigned to the genus Apteodinium (Eisenack) Lucas-Clark 1987, due to the general outline, the prominent apical horn, the complexity of the wall with a microreticulate to spongy aspect according to the focus level, and the paratabulation hardly discernible. The best comparison could be made with A. granulatum (Eisenack) Lucas-Clark 1987. However, the distal network of trabeculae linking tips of adjacent pila or clava is here much less
333
THREE NEW DINOFLAGELLATE CYSTS FROM MOROCCO
i
o
Fig.6. Paratabulation pattern (Taylor-Evittnotation) of Liesbergiaabdounensissp. nov. interpreted from discernibleparasutural ridges. (a) external view of dorsal side. (b) external view of ventral side. dense than on any Apteodinium species. No true outer layer can be delineated at high magnification, even discontinuous (Plate II, 9). The autophragm is variously ornamented but not 2 or 3-layered as described by Lucas-Clark (1987) for A. granulatum. Consequently, it seems unappropriate to consider the apical horn as a "cavation", as Sarjeant (! 985) does about A. granulatum. The apical horn is here a projection of trabeculae, more or less loosely linked together (Fig.5). Although it is hardly discernible, paratabulation pattern has been partially reconstructed (Fig.6). It shows a typical affinity with Gonyaulax-type cysts, permanently excluding the attribution to any Apteodinium or Aldorfia species (cf. Cribroperidinium and Aptiana-Ventriosum Complex, Helenes, 1986; Lucas-Clark, 1987). Among Evitt's Leptodinium Complex (1985), Acanthaulax is the most appropriate genus to compare moroccan specimens with, although these do not show any spine on parasuttural ridges or in intratabular ornamentation (Sarjeant, in Davey el al., 1966). The characteristic "dense spine cover" (Sarjeant, in Davey et al., 1966) is here a dense (simple or bifurcate) pila or clava cover. Moreover, the genus Liesbergia Berger 1986 has been erected to differentiate Acanthaulax-type cysts with a highly distinctive apical horn "only formed by development of the external ornamentation and not the entire periphragm" (Berger, 1986). Except the nature of ornamentation on the cyst surface (and their stratigraphic distribution),
L. scarburghensis (Sarjeant) Berger 1986 and moroccan cysts are quite similar, both showing "an irregular reticulate patterning" (Sarjeant, 1961) in over view of the wall surface, made of spiny projections more or less linked together on the former (low ridges described by Sarjeant, 1961), made of rounded projections (clava or pila) with, sometimes, connected tips on the latter. L. liesberghensis Berger 1 9 8 6 differs from L. abdounensis in having a scattered ornamentation and fewer trabeculae building the apical horn. About the characteristics of the genus Liesbergin, Berger's diagnosis lacks information about paraplates arrangements. A reexamination of Liesbergia type material should be of great interest to compare Paleogene and Jurassic specimens. Remark: The stratigraphic gap between L. liesbergensis and L. scarburghensis (Oxfordian) and L. abdounensis (Thanetian-Ypresian) may be filled, perhaps, with a systematic review of all socalled Apteodinium cysts at high magnification: presumed non-tabulate taxa often prove to be "cryptotabulate" in fact. Then, one could discover some "Apteodinium" specimens with a paratabulation pattern not belonging to Aptiana-Ventriosum Complex but to Gonyaulacysta-type, during the Cretaceous interval. Perhaps new species of Liesbergia could then be erected. Genus Spinidinium (Cookson and Eisenack) Lentin and Williams 1976
Type species: Spinidinium styloniferum Cookson and Eisenack 1962. Rakish's bore, Australia. Aptian-?Albian Spinidinium stellatum sp. nov. Holotype: Plate III, 1-3. Palynological sample and slide 16395-Z level 76, borehole SB 19, Oulad Abdoun, Morocco. England Finder references: Q 34. Paratype 1: Plate III, 5-7. Palynological sample and slide 16393-I', level 71, borehole SB 19, Oulad Abdoun, Morocco. England Finder references: Y 45-1. Paratype 2: Plate III, 8, 9. Palynological sample and slide 14402-1, level 55, borehole $4, Oulad
tml
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335
THREE NEW DINOFLAGELLATE CYSTS FROM MOROCCO
Abdoun, Morocco. England Finder references: W 29-2. Derivation of name: stellatum: from stella (latin), in reference to the star-shaped tip of the projections Type locality: Al Borouj, Oulad Abdoun phosphate basin, Morocco Stratigraphic horizon: Thanetian, Borehole SBI9, levels 76, 74, 71, 69, 65, Thanetian to Thanetian/ Ypresian boundary, Borehole $4, levels 57, 55, 54, 51 Relative abundance: Very abundant (almost monospecific) to unfrequent Diagnosis: Rounded polygonal, compressed dorsoventrally, proximochorate two-layered cyst, circumcavate (to bicavate). Short apical horn truncated, left antapical horn variable in length, pointed, right antapical reduced or absent. Broad and laterally prominent paracingulum. Numerous projections on cyst surface, variable in length and shape complexity. Tapering proximally, with pericoele often protruding into their base; solid stem short to long, narrow to broad; distal part simple, bifurcate, trifurcate or more; at any scale, every distal extremity expanding and aculeate. Paratabulation evident (except in paracingular and parasulcal areas), peridinioid ortho- (ventral side) hexa type (dorsal side). Projections in parasutural position on ventral side, in penitabular position on
dorsal side, partially missing on 2a intercalary paraplate (border-side with 4") and on 3'" (borderside with paracingulum), absent in the paracingulum and the sulcal areas. Strong antapical dissymmetry, 2"" large and almost centered, 1"" reduced to the left antapical horn. Pedo and endo-archeopyle type Ia, eurydeltaform. Pedoperculum commonly adnate, endoperculum adnate, rarely discernible. Dimensions: holotype length: 95.5 I~m, width: 77 pm; range length: 67-116.5 llm, width: 60.5-112 I~m; processes length: 2-9.5 ~tm (homogeneous on each specimen); 120 specimens measured. Description: Spinidinium stellatum cysts are twolayered, the endophragm is thin and smooth, spheroidal, variably appressed to the periphragm (circumcavate to bicavate). The periphragm is generally smooth or shagrinate, but sometimes fove !ate (Plate IIl, 5, 6). Straight, long and simple projections are particularly well developed on the extremities of apical and antapical horn (Hate III, 4). Paracingulum borders are also prominent, underlined by more complex projections: simple, bifid or trifid, they can be linked together proxi-
PLATE III
Spinidinium stellatum sp. nov. Bar-scale 20 lam= x 500 (1-12), Bar-scale 10 l~m= x 1500 (13-14). 1-3 Holotype 1. External view/dorsal side, slide 16395-2, England Finder references Q 34, borehole SB 19, level 76. 2. Medium focus, same coordinates. 3. Internal view/ventral side, same coordinates. 4. Medium focus, slide 16393-4, E.F. ref. J 35-3, borehole SB 19, level 71. Note the adnate endoperculum. 5-7 Paratype 1. 5. External view/dorsal side, slide 16393-1", E.F. ref. Y 45-1, borehole SB 19, level 71. 6. Lower external view, same coordinates. Note the foveolate surface of the periphragm. 7. Internal view/ventral side, same coordinates. 8, 9. Paratype 2. 8. Medium focus, slide 14402-1, E.F. ref. W 29-2, borehole $4, level 55. 9. Internal view/ventral side, same coordinates Note the complexity of processes tip, discernible at low magnification. 10. External view/dorsal side, slide 16395-1, E..b. ref. S 34-I, borehole SB 19, level 76. Note the great dimensions of this specimen. I 1. Internal view/dorsal side, slide 16394-1', E.F. ref. P 33-4, borehole SB 19, level 74. Distinct dorsal hypocyst arrangement of paraplates. 12. External polar view (hypocyst), slide 16394-1', E.F. ref. P 42-4, borehole SB 19, level 74. Note the dorso-ventral compression of the cyst. 13. External view/ventral side, detail of epicyst processes tip, slide 16394-1', E.F. ref. U 37-3, borehole SB 19, level 74. 14. External view/dorsal side (hypocyst), slide 16394-1', E.F. ref. W 44-3, borehole SB 19, level 74.
336
M.-J. SONCINI
...' i f ' ; : • ~.,
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Fig.8. Paratabulation pattern (Kofoid notation) of Spinidinium stellatum sp. nov. reconstructed from parasutural and penitabular ornamentation. (a) external view of ventral side. (b) internal view of dorsal side.
Fig.7. Sketch drawing of varying projections features (spines, diminutive processes) observed in optical section on Spinidinium stellatum sp. nov.
genus Spinidinium, S. stellatum differs greatly from other Spinidinium species: with the penitabular and parasutural distribution of the projections (commonly covering the surface of the cyst except on pandasutural areas on other paratabulated Spinidinium species); with the complexity of these projections: short to long spines (like most Spinidinium) or diminutive processes typically expanded and aculeate (very distinctive character). Some features in S. stellatum suggest morphological affinities with the Wetzeliellaceae: processes distribution could compare with some Wilsonidium Lentin and Williams 1976, but not the ambitus (no equatorial extension for instance); distal rows of minute spines on narrow processes tip could compare with ornamentat, on on some Apectadinium (Costa and Downie) Lentin and Williams 1977, but paratabulation is generally not clear on Apectodinium cysts. However, in no case Spinidinium stellatum ~hows the characteristic quadra-type dorsal organization of the Wetzeliellaceae (2a quadra, large and broad 4"), nor the para ventral organization (/'contacts 2" and 6"). Remark: In the moroccan succession of dinocysts assemblages (Soncini, 1990), Spinidinium stellatum appears contemporaneously with a Spinidinium acme (S. aft. ?pilatum (Stanley) Costa and Downie 1979, S. densispinatum Stanley 1965, S. macmurdoense (Wilson) Lentin and Williams 1976, S. pulchrum (Benson) Lentin and Williams 1977), slightly preceeding the appearance of the Wetzeliellaceae: Apectodinium homomorphum -
mally in a discontinuous ridge. Although they are homogeneous on a single specimen, projections show a great diversity in shape and length (Fig.7); it is then hard to call them "spines" or "processes". With short or long, narrow or broad solid stem, straight or branched, bifid, trifid, they are all distally expanded and aculeate, but the rows of minute acuminate spines are hardly discernible (Plate III, 13, 14). Anyway, the first stricking feature all projections have in common is their roughly star-shaped tip (hence the species name: stellatum). Projections are scarce on paraplates surface, but numerous in parasutural position on ventral side (Plate III, 3), and in penitabular position on dorsal side (Plate III, 1, 10, 11) (rare specimens with just few "diminutive processes" underlying paratabulation). Lack of projection on posterior margin of intercalary paraplate 2a (contact 2a/u"), and on the anterior margin of postcingular paraplate 3"' (contact 3'"/paracing.) are also diagnostic features (Fig.8). Paratabulation peridinioid, with ventral ortho-type. Dorsally, la and 3a intercalaries seem to be smaller than the six-sided 2a (hexa-type). The archeopyle (type Ia) is eurydeltaform (Plate III, 1), the operculum (2a) is generally adnate (Plate III, 10). The endoperculum is also adnate and eurydeltaform, sometimes discernible inside the cyst (Plate III, 4). Comparison: Although it belongs clearly to the
-
THREE NEW DINOFLAGELLATE CYSTS FROM MOROCCO
appears 5 m higher than S. stellatum in SB 19 and 2 m higher than S. stellatum in $4 in the upper part of the Thanetian. The acme of the Wetzeliellaceae occurs le.ter, 5m above appearance of A. homomorphum in $4, in the basal Ypresian.
Conclusion The rich dinoeyst microflora from the phosphate deposits of Morocco (Oulad Abdoun basin, Phosphate Plateau) has yielded two new gonyaulacoid taxa and one new peridinioid species. Bituberieysta boroujiana gen. nov. et sp. nov. has morphological characters in common with Cordosphaeridium exilimurum but appears later, in "Ypresian deposits, where they are present together (jointly with the beginning of the ~tzeliellaceae acme). From the paratabulation pattern point of view, Bituberieysta shows close affinities with Danea and can probably be considered as a new member of the Daneagroup. Liesbergia abdounensis sp. nov. is present during Thanetian to Ypresian times. Finally, Spinidinium stellatum sp. nov. is typical of Thanetian deposits and seems to have a maximum range limited to the basal Ypresian. This abundant taxon will probably prove to be a good index species ['or Paleocene/Eocene stratigraphic boundary, slightly preceeding the index apl~ ~arance of the Wetzeliellaceae.
Acknowledgements I am indebted to the Laboratory of Palynology staff (Centre de G6ochimie de ia Surface, Strasbourg, France) for conceeding me access and use to tb,,~r microscope, computers and photographic laboratory. I wish to thank Mr. R. Rauscher who provided much helpful discussion and criticism about systematics and latin terminology. He is also gratefully acknowledged for his critical reading of the manuscript. For his helpful participation in the drawings, I also thank Mr. C. Hamel.
References Archangelsky, S. 1969. Sobre el paleomicroplancton del Terciario Inferior de Rio Turbio, Provincia de Santa Cruz. Ameghiniana, 5: 406-416. Belfkira, O., 1980. Evolutions s6dimentologiques et g~ochim-
337 iques de la s6de phosphat6e du Maastrichtien des Oulad Abdoun (Maroc). These, Univ. Scientifique M6dicale Grenoble, 164 pp. Benalioulhaj, S., 1989. Geochimie organique compar6e des s6ries du Bassin phosphat6 des Oulad Abdoun et du Bassin de schistes bitumineux de Timahdit (Maroc). Implications dans la phosphatogen6,~e. Th6se, Univ. Orl6ans, 266 pp. Berger, J.P., 1986. Dinoflagellates of the Callovian-Oxfordian boundary of the "Liesberg-Dorf'" quarry (Berner Jura, Switzerland). Neues Jahrb. Geol. Palfiontol. Abh., 172, 3: 331-355. Cookson, I. and Eisenack, A., 1962. Additional microplankton from Australian Cretaceous sediments. Micropaleontology, 8(4): 485-507. Costa, L.I. and Downie, C., 1979. The Wetzeliellaceae; Paleogene dinoflagellates. Proc. IV Inter. Palynol. Conf., Lucknow (1976-1977), 2: 34-46. Damassa, S.P., 1984. Morphologic variability and paraplate configuration of the dinoflagellate genus Danea Morgenroth 1968. Palynology, 8: 51-69. Davey, R.J., 1969. The evolution of certain Upper Cretaceous hystrichospheres from South Africa. Palaeontol. Afr., 12: 25-51. Davey, R.J., Downie, C., Sarjeant, W.A.S. and Williams, G.L., 1966. Studies on Mesozoic and Cainozoic dinoflagellate cysts. Bull. Br. Mus. Nat. Hist. Geol., Suppl. 3, 248 pp. Drugg, W.S., 1970. Some new genera, species, and combinations of phytoplankton from the Lower Tertiary of the Gulf Coast, U.S.A.N. Am. Paleontol. Conv., Chicago, 1969, Proc. G., pp.809-843. Evitt, W.R., 1985. Sporopollenin DinoflageUate Cysts, Their Morphology and Interpretation. A.A.S.P. Found., Dallas, TX, 333 pp. Helenes, J., 1986. Some variations in the paratabulation of gonyaulacoid dinoflagellates. Palynology, 10: 73-110. Lentin, J.K. and Williams, G.L., 1976. A monograph of fossil peridinioid dinoflagellate cysts. Bedford Inst. Oceanogr. Rep. Ser., BI-R-75-16: 1-237. Lentin, J.K. and Williams, G.L., 1977. Fossil dinoflagellates: Index to genera and species, 1977 edition. Bedford Inst. Oceanogr. Rep. Ser., BI-R-77-8: 1-209. Lucas-Clark, J., 1987. Vigginsiellan. gen., Spongodinium and Apteodinium as members of the Aptiana-Ventriosum Complex (fossil dinophyceae). Palynology, 11: 155-184. Rauscher, R., Soncini, M.-J., Benalioulhaj, S. and Trichet, J., 1990. Les phosphates s6dimentaires, un milieu de conservation exceptionnel de la mati6re organique. Apports de la g6ochimie organique et de la palynologie. C. R. Acad. Sci. Pads, 310, II: 613-618. Sarjeant, W.A.S., 1961. Microplankton from the Kellaways Rock and Oxford Clay of Yorkshire. Palaeontology, 4(1): 90-d 18. Sarjeant, W.A.S., 1964. New name and diagnosis for an Upper Jurassic species of Gonyaulacysta (Dinophyceae). Palaeontology, 7(3): 472-473. Sarjeant, W.A.S., 1981. A restudy of some dinoflage!late cysts holotypes in the University of Kiel Collections. II. The Eocene holotypes of Barbara Klumpp (1953); with a revision of the genus Cordosphaeridium Eisenack, 1963. Meyniana, 33:97-132.
338
Sarjeant, W.A.S., 1985. The german Aptian dinoflagellate cysts of Eisenack (1958): a restudy. Rev. Palaeohot. Palynol., 45: 47-106. Soncini, M.-J., 1990. Palynologie des phosphates des Oulad Abdoua (Maroc). Biostratigraphie et environnements de la phosphatogen6se dans le cadre de la crise Cr6tac6 - - Tertiaire. These, Univ. Louis Pasteur, Strasbourg, 243 pp. Soncini, M.-J. and Rauscher, R., 1988. Associations de dinokystes du Maastrichtien-Pal6oc6ne phosphat6 au Maroc. Bull. Centres Rech. Explor.-Prod. Elf-Aquitaine, 12(1): 427-450. Soncini, M.-J. and Rauscher, R., 1990. Morphologies particu-
M.-J. $ONCINI
li6res chez les dinokystes des genres lsabelidinium, Manumiella et £,inogymnium dans les phosphates maastrichtiens et pal6oc6nes du Maroc. Bull. Centres Rech. Explor.-Prod. Elf-Aquitaine, 14(2): 583-596. Stanley, E.A., 1965. Upper Cretaceous and Paleocene plant microfossils and Paleocene dinoflagellates and hystrichosphaerids from northwestern South Dakota. Bull. Am. Paleontol., 49(222): 179-384. Stover, L.E. and Evitt, W.R., 1978. Analyses of Pre-Pleistocene organic-walled dinoflagellates. Stanford Univ. Publ. Geol. Sci., 15, 300 pp.
325
Elsevier Science Publishers B.V., Amsterdam
Three new dinoflagellate cysts from the Moroccan PaleoceneEocene phosphates M a r i e - J o Soncini Universitb Louis Pasteur, Institut de Gdologie, 1 Rue Blessig, 67084 Strasbourg Cedex, France (Received July 9, 1991; revised and accepted October l I, 1991)
ABSTRACT Soncini, M.-J., 1992. Three new dinoflagellatecysts from the Moroccan Paleocene-Eocene phosphates. Rev. Palaeobot.
Palynol., 70: 325-338. Moroccan phosphate deposits from the Phosphate Plateau (Oulad Abdoun basin, near Khouribga)contain varied and well preserved dinoflagellate cysts. Among them, a new genus: Bitubericysta and three new species: B. boroujiana, Liesbergia abdounensis and Spinidinium stellatum are described in this paper. The two gonyaulacoidcysts have been found in Upper Paleocene (Thanetian) and Lower Eocene (Ypresian) sediments, the peridinioid cyst has been observed in Upper Paleocene (Thanetian) and basal Eocene (basal Ypresian) material.
Introduction The new dinoflagellate cysts presented in this paper belong to a rich and varied dinocysts flora recently studied (Soncini, 1990). As the organic matter lacks maturity in Moroccan phosphates in the Oulad Abdoun basin (Benalioulhaj, 1989), the dinocysts also present in this material lack both stiffness and colouration but they are well preserved (Soncini and Rauscher, 1988; Rauscher et al., 1990). This is not the case with calcareous nannofossils and foraminifera which have not been studied. Pollen grains are rare, hardly reaching 2% of the total palynomorph content in 2 levels out of a hundred. Age assignments then are strictly based on dinocysts (Soncini, 1990). The three new species of dinocysts described here, one of which belongs to a new genus, have been observed in the upper part of the two boreholes under study: SB !9 and $4 (Fig. l). Spinidinium stellatum is typically present in Thanetian levels and at the Thanetian/Ypresian boundary (Figs.2, 3). Liesbergia abdounensis has been observed in both Thanetian and Ypresian levels 0034-6667/92/$05.00
(Figs.2, 3) and Bitubericysta boroufiana is restricted to lower Ypresian levels (Fig.2). There is no possibility of finding the two gonyaulacoid cysts higher in the phosphatic lithological series of SB 19 borehole (Eocene ?) as the material has been oxidized and washed out by meteoritic waters. Comprehensive lithological, sedimentary, geochemical descriptions of the Maastrichtian-Paleocene-Eocene phosphatic series in the Oulad Abdoun can be found in Belfkira (1980; borehole SB 19, among others) and in Benalioulhaj (1989; borehole $4, among others). Holotypes, paratypes and other figured specimens of the three species described are housed in the palynological slide collection of the Laboratoire de Palyno!ogie, Centre de G6ochimie de la Surface, Strasbourg, France. All photographs are made with a Vario Orthomat system on a Leitz Ortholux II microscope, using interferential contrast.
Systematic palynology Division PYRROPHYTA Pascher 1914 Class DINOPHYCEAEFritsch 1935
© 1992-- ElsevierSciencePublishers B.V. All rights reserved
326
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Fig.3. Stratigraphy and lithology of SB 19 borehole (Oulad Abdoun, Morocco) and stratigraphic range of Liesbergia abdounensis and Sp#ffdinium stellatum.
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Genus Bitubericysta gen. nov.
Diagnosis: Cyst spheroidal, skolochorate, twolayered. Thin endophragm closely appressed to fibro-pitted periphragm variable in thickness. Intra-tabular processes well-developed, arising from the periphragm only, indicating a complete gonyaulacacean paratabulation, with a Danea-type organization. Small apical protrusion broad and solid. Processes fibrous and hollow, simple buccinate to complexely divided, expanding distally and irregularly recurving in a spinous margin. Annular to soleate antapical complex, surrounding a solid periphragmal protrusion variable in length. Archeopyle type P (4), operculum h'ee.
Type species: Bitubericysta boroujiana gen. nov. et
Bitubericysta boroujiana sp. nov.
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Fig.2. Stratigraphy and lithology of $4 borehole (Oulad Abdoun, Morocco) and stratigraphic range of Bitubericysta boroujiana, Liesbergia abdounensis and Spinidinium stellatum.
Order
PERIDINIALES
Haeckel 1894
sp. nov.
Holotype: Plate I, 1-3. Palynological sample and Derivation of name: Bitubericysta: from bi-tuber (latin), two protrusions, for apical and antapical features
slide 14409-1, level 45, Borehole $4, Oulad Abdoun, Morocco. England Finder references: U 35.
327
THREE NEW DINOFLAGELLATE CYSTS FROM MOROCCO
Paratype: Plate I, 9-1 I. Palynological sample and slide 14409-1, level 45, Borehole $4, Oulad Abdoun, Morocco. England Finder references: S-T 37. Derivation of name: boroufiana: in reference to Al Borouj, near Khouribga, in the vicinity of the borehole Type locality: Ai Borouj, Oulad Abdoun Phosphate Basin, Morocco Stratigraphic horizon: Ypresian, Borehole $4, level 45 Relative abundance: abundant (17%) Diagnosis: Spheroidal, skolochorate, two-layered cyst. Thin endophragm closely appressed to fibropitted pedphragm variable in thickness. Processes well developed, hollow and fibrous, arising from periphragm only; simple buccinate (precingular and II, Ill, VI postcingular) to complexely divided (IV and V postcingular), distally expanding and recurving in an irregular spinous margin. One process per paraplate, reflecting a complete gonyaulacacean paratabulation with a Danea-type organization. Paracingular processes tubular to latispinous, simple or divided, parasulcai ones simple and slender. Bifurcate or trifurcate apical protrusion, short, broad and solid, made by periphragm only. Annular to soleate antapical complex surrounding a solid periphragmal protrusion variable in length. Archeopyle type P (4), operculum free. Dimensions: holotype maximum diameter: 123.5 l~m, maximum processus length: 39.5 l~m, antapical protrusion: 14 ~tm; range maximum diameter: 103-(126)-152 l~m, maximum processus length: 32.5(41)-54 l~m, antapical protrusion: 7-(13)- 18.5 om; periphragm thickness (without polar protrusion and process): 2.5-5.5 ~tm; endophragm thickness: 1.5-2 ~tm; 15 specimens measured. Description: Bitubericysta cysts are typically spheroidal. The polar features are very distinctive but variab!e. The apical protrusion is solid and exclusively periphragmal: endocoele is not involved in this feature and less than 1% of the population show the endophragm slightly protruding into one or both polar projections; it is bifid or trifid,
massive, and typically linked to the proximal part of the process from apical paraplate B (Plate I, 3-6, Plate II, l). The antapical pole is also highly distinctive by the periphragmal protrusion, shorter than processes but variable in length (7 to 18.5 llm), commonly with a rounded tip, associated with a soleate complex of long and loosely fibrous projections, more or less linked laterally and distally (Plate I, 2, 7, 8, 10). This complex is open on ventral side (Plate I, 2, 10). Other processes are clearly intratabular, tubular, hollow, open distally. In paracingular area, processes are tubular or slightly flattened to latispinous on dorsal side (Plate I, 3), i.e. they are elliptical in cross-section, perpendicularly to the polar axis. They are simple, distally expanded in a paintbrush-like fashion. They can also be divided more or less close to their proximal part (bifurcate, trifurcate, complex...), particularly on dorsal side, but they clearly reflect 6 paracingular paraplates (Fig.4). In parasulcal area, l i, ai, fu, li, Ira, Iu, X and Z processes are discernible (Plate I, l, I l). Processes are hollow, slender and buccinate, with a spinous slightly recurved margin, densely fibrous, only lu possibly showing distal branching. Process of paraplate// is also smaller than pre- and postcingulars and can be incorporated in a parasulcai group in which processes depict faint alignments as follows: li and ai equal medium size, parallel to paracingulum organization; fu, Iu, II in a growing size order, not parallel to paracingulum but bending towards antapical pole; Ii, Ira, X in a growing size order, t
[3"
[]
b
,zorn, dorsal side
ventral side
Fig.4. Paratabulation pattern (Taylor-Evitt notation) of Bitubericysta boroujiana gen. et sp. nov. interpreted from processes distribution. Each process is represented by its proximal section. (a) external view of dorsal side. (b) external view of ventral side.
III
t'rl
t"
O0
329
THREE NEW DINOFLAGELLATE CYSTS FROM MOROCCO
in a diagonal arrangement; and Z slightly offset on the right side, below the large process of postcingular paraplate VI (Fig.4). Apical and precingular processes are larger (A and li smaller than B and C, 2 and 5 smaller than 3 and 6), densely to loosely fibrous, sometimes fenestrate. They are commonly simple tubular, largely expanded distally in paintbrush-like fashion. Distal margin is irregularly recurved and spinous. Postcingulars are comparable to precingulars on ventral side (Ill, VI) but larger, proximally tubular, more or less divided and largely expanded distally. On dorsal side (IV, V), processes are complexely divided, proximally arranged in an arcuate to soleate feature, opened towards the apex (Plate I, 3, 9). The plate boundary between IV and V complexes is then situated in a middorsal position, facing the archeopyle (Fig.4). Comparisons: At first sight, Bitubericysta is similar to Cordosphaeridium (Eisenack) Davey 1969: spheroidal shape, fibro-pitted to fibrous periphragm, intratabular position of processes reflecting a gonyaulacacean paratabulation pattern. Global aspect of processes compares well with C. exilimurum Davey and Williams in Davey et al. 1966. However, solid, periphragmal projections have never been described by authors on Cordosphaeridium: "not distinctive" apical and antapical processes are depicted by Davey (1969), or a slightly distinctive
antapical process (longer) is mentioned by Sarjeant (1981). In fact, there are always small to great differences (polar features for example) between Bitubericysta and the few other fibrous dinocysts which seem to show some morphological resemblance with it (Table l): Amphorosphaeridium Davey 1969 or Fibrocysta Stover and Evitt 1978, for example. As regards the paraplates organization, Bitubericysta proves close affinities with Danea (Morgenroth) Drugg, 1970, in spite of important morphological differences between the two genera (penitabular or intratabular septa frequent to dominant among projections on Danea dinocysts for example). As there are also morphological differences between Bitubericysta and the other "Danea-type'" dinocysts (Damassa, 1984) like Turbiosphaera Archangelsky 1969 (Table l), Bitubericysta will, perhaps, be considered as a new member of the Danea-group (Damassa, 1984)? Genus Liesbe~'gia Berger 1986
Type species: Liesbergia liesbergensis Berger 1986 Early Oxfordian, Liesberg Dorf, Berner Jura, Switzerland. Liesbergia abdounensis sp. nov. Holotype: Plate II, 4-6. Palynological sample and slide 14404-1, level 51, Borehole $4, Oulad
PLATE !
Bitubericysta boroujiana gen. et sp. nov. Bar-scale 20 p.m for all photographs = x 300, except 4 and 8: bar-scale l0 prn -- × 450. 1-3. Holotype. I. External view/ventral side, slide 14409-1, England Finder references U 35, borehole $4, level 45. 2. Medium locus/ventral side, same coordinates. 3. Internal view/dorsal side, same coordinates. Note the soleate processes complex on IV postcingular paraplate and the latispinous paracingular processes. 4. Medium focus, slide 14409-1, E.F. ref. L 50-1, borehole $4, level 45. Detail of preapical "process-protrusion' linked to apical process of paraplate B. Note the fenestration of B. 5. External view/dorsal side, slide 14409-1, E.F. ref H 34-2, borehole $4, level 45. Clear focus on apical C process and central tip of preapical "process-protrusion". 6. Lower focus, same coordinates. Clear focus on apical B process and lateral tip of preapical "process-protrusion'. Note the link between B and the apical protrusion. 7. Focus series from external view/dorsal side to optical section, slide 14409-1, E.F. ref. H 34-2, borehole $4, level 45. 8. Detail of antapical organization of projections (protrusion and pr,~cesses), slide 14409-1, E.F. ref. L 40-3, borehole $4, level 45. 9-11. Paratype. 9. Internal view/dorsal side, slide 14409-1, E.F. ref. S-T 37, borehole $4, level 45. Note the soleate processes complex on IV and V postcingular parapiates. 10. External view/ventral side, same coordinates. Note the antapical protrusion. I I. Higher focus/ventral side, same coordinates.
tm.I
t"tl
t"
331
THREE NEW DINOFLAGELLATE CYSTS FROM MOROCCO
TABLE 1 Comparison of diagnostic features of Bitubericysta gen. nov. with morphologically similar fibrous genera (archeopyle type ! P) Bitubericysta
Cordosphaeridium
Turbiosphaera
Amphorosphaeridium
Fibrocysta
spheroidal
ovoidal
ovoidal
periphragm + endophragm 1 antapical 1 apical
periphragm + endophragm none
periphragm + endophragm none
spheroidal to ovoidal periphragm + endophragm none
tabular l/paraplate buccinate, expanded + branched distally, hollow distinct
tabular l/paraplate buccinate, expanded + branched distally, solid or hollow distinct
tabular l/paraplate wide and flat to membranous
strictly non tabular or occasional tabular tubiform, spinous distally, hollow
non tabular
undistinct
undistinct
no yes
no yes (slightly)
distinct to partially problematical yes yes
yes yes (usually)
yes yes (sometimes)
CENTRAL BODY Shape spheroidal layers polar protrusion(s) PROCESSES distribution shape and structure
paratabulation
distinctive apical distinctive antapical
Abdout~, X 54.
Morocco.
England
F i n d e r references:
Paratype 1: Plate II, 2, 3. Palynological sample a n d slide 14404-1, level 51, Borehole $4, O u l a d A b d o u n , M o r o c c o . E n g l a n d F i n d e r references: O 54-3. Paratype 2: Plate II, 7, 8. Palynological sample
autophragm ! apical + ! antapical
slightly expanded or branched distally
and slide 14404-1, level 51, B o r e h o l e $4, O u l a d A b d o u n , M o r o c c o . E n g l a n d F i n d e r references: U 51-4. Derivation o f name: abdounensis: in reference to the O u l a d A b d o u n P h o s p h a t e Basin ( M o r o c c o ) Type locality: A! Borouj, O u l a d A b d o u n p h o s p h a t e basin, M o r o c c o
PLATE II Bar-scale 20 I~m= x 500.
I. Bitubericystaboroufianagen. et sp. nov. External view/right lateral side, slide 14409-1, England Finder references P 42, borehole $4, level 45.
2-9 Liesbergia abdounensissp. nov. 2, 3. Paratype 1. 2. Internal view/right lateral side, slide 14404-I, E.F. ref. O 54-3, borehole $4, level 51. Note the low relief of parasutures. 3. Medium focus, same coordinates. Note the elongation of periphragm projections building the apical horn. 4-6 Holotype 4. External view/left lateral side, slide 14404-1, E.F. ref. X 54, borehole $4, level 51. 5. Lower focus (partially external, partially internal or optical section), same coordinates. Note the apical elongation and intrication of projections building the apical horn. 6. Internal view/right lateral side, same coordinates. 7, 8. Paratype 2. 7. External view/ventral area, slide 14404-1, E.F. ref. U 51-4, borehole $4, level 51. Note the 6/A/li parasutures contacts and lu/2 parasuture contact. 8. Internal view/mid-dorsal-left lateral side, same coordinates. Note the apical elongation and intrication of projections building the apical horn. 9. Internal view/dorsal side, slide 14404-I, E.F. ref. Y 48-2, borehole $4, level 51. Paracingulum area broken under the archeopyle. Note the relation between projections and inner part of autophragm surface.
332
Stratigraphic horizon: Thanetian, Borehole SB 19, level 65, Ypresian, Borehole $4, levels 51, 49, 46 Relative abundance: rare in each level Diagnosis: Proximate, acavate, subspherical to subpolygonal cyst. Prominent truncated apical horn, broad-based, consisting of anastomosed trabeculae. External surface of autophragm covered by a dense pilate or clavate ornamentation, with occasional distal connections. Basal part of autophragm generally slightly protruding into the apical trabecular structure. Complete paratabulation underlined by ridges of distally linked projections, higher than intratabular ornamentation. Gonyaulacoid sexiform, Gonyaulacysta-type arrangement of paraplates. Distinctive topology of ventral area: A contacts ai, li narrow, roughly triangular, not in contact with lu, A larger than lu. Archeopyle P(4), operculum free. Dimensions: holotype maximum length: 104.5 lam, maximum widt'l: 81 ~tm, apical horr.: 14 lam; range maximum length including apical horn: 70-105 ~tm (89 lxm), maximum width: 60-85 ~tm (71 ~tm), maximum length of apical horn, between wall and tip of projections: 7-19 ~tm (12.5 ~tm); thickness of wall including surface's ornamentation: 2-4 lxm; parasutural ridges: 4.5-5.5 ~tm; 15 specimens measured. Description: Moroccan cysts described here are proximate, acavate, subspherical to subpolygonal in outline; the hypocyst is rounded, and the epicyst is subconical (Plate II, 2). The prominent apical horn is variable in length, with a broad basis and a truncated tip. It consists exclusively of anastomosing "trabeculae, coming from the elongated elements of ornamentation (Fig.5). Autophragm bears a dense ornamentation on external surface (Plate II, 9), formed by short projections with rounded tips, that can be simple, bifurcate, and sometimes distally linked (Fig.5), drawing an irregular reticulate and granulate patterning in high focus observation. No continuous external layer can be delimited. The basal part of the autophragm generally shows a small protrusion into the apical
M.-J. SONCINI
Fig.5. Sketch drawing of the apical horn of Liesbergia
abdounensis sp. nov.
anastomosed trabeculae structure (variable character) (Plate II, 9). A narrow paracingulum is delimited by two ridges formed by anastomosing and/or distally linked projections. The parasulcus is slightly hollow, with an ornamentation of lower relief. Archeopyle is of type P(4), the operculum is free. All the parasutures are underlined by ridges of irregular height, higher than intratabular ornamentation (Plate II, 2, 4-8) and composed of distally linked projections. Paratabulation is Gonyaulacoid, of Gonyaulacysta-type (Fig.6). The apical area has not been observed; A/lu, B/C, C/A parasutures all disappear in the apical trabeculate network of the horn (Plate II, 9). There is a 6-sided central antapical paraplate Y (sexiform), probably in symmetrical arrangement (cf. text-fig. 2, Helenes, 1986). The ventral area seems to show a sigmoidal sulcus: S-type organization (Evitt, 1985). The arrangement of paraplates on ventral epicyst is hardly discernible (Plate II, 7), but 1i is evidently narrow, roughly triangular-shaped and clearly not in contact with lu. Consequently, A contacts ai: A/ai arrangement (Helenes, 1986). A is larger than lu, and there is no obliteration of their parasuture, li, Im, lu are not distinct. Complete paratabulation of precingular, paracingular and postcingular areas have been observed (Fig.6). Comparison: At first sight, the moroccan dinocysts described could be assigned to the genus Apteodinium (Eisenack) Lucas-Clark 1987, due to the general outline, the prominent apical horn, the complexity of the wall with a microreticulate to spongy aspect according to the focus level, and the paratabulation hardly discernible. The best comparison could be made with A. granulatum (Eisenack) Lucas-Clark 1987. However, the distal network of trabeculae linking tips of adjacent pila or clava is here much less
333
THREE NEW DINOFLAGELLATE CYSTS FROM MOROCCO
i
o
Fig.6. Paratabulation pattern (Taylor-Evittnotation) of Liesbergiaabdounensissp. nov. interpreted from discernibleparasutural ridges. (a) external view of dorsal side. (b) external view of ventral side. dense than on any Apteodinium species. No true outer layer can be delineated at high magnification, even discontinuous (Plate II, 9). The autophragm is variously ornamented but not 2 or 3-layered as described by Lucas-Clark (1987) for A. granulatum. Consequently, it seems unappropriate to consider the apical horn as a "cavation", as Sarjeant (! 985) does about A. granulatum. The apical horn is here a projection of trabeculae, more or less loosely linked together (Fig.5). Although it is hardly discernible, paratabulation pattern has been partially reconstructed (Fig.6). It shows a typical affinity with Gonyaulax-type cysts, permanently excluding the attribution to any Apteodinium or Aldorfia species (cf. Cribroperidinium and Aptiana-Ventriosum Complex, Helenes, 1986; Lucas-Clark, 1987). Among Evitt's Leptodinium Complex (1985), Acanthaulax is the most appropriate genus to compare moroccan specimens with, although these do not show any spine on parasuttural ridges or in intratabular ornamentation (Sarjeant, in Davey el al., 1966). The characteristic "dense spine cover" (Sarjeant, in Davey et al., 1966) is here a dense (simple or bifurcate) pila or clava cover. Moreover, the genus Liesbergia Berger 1986 has been erected to differentiate Acanthaulax-type cysts with a highly distinctive apical horn "only formed by development of the external ornamentation and not the entire periphragm" (Berger, 1986). Except the nature of ornamentation on the cyst surface (and their stratigraphic distribution),
L. scarburghensis (Sarjeant) Berger 1986 and moroccan cysts are quite similar, both showing "an irregular reticulate patterning" (Sarjeant, 1961) in over view of the wall surface, made of spiny projections more or less linked together on the former (low ridges described by Sarjeant, 1961), made of rounded projections (clava or pila) with, sometimes, connected tips on the latter. L. liesberghensis Berger 1 9 8 6 differs from L. abdounensis in having a scattered ornamentation and fewer trabeculae building the apical horn. About the characteristics of the genus Liesbergin, Berger's diagnosis lacks information about paraplates arrangements. A reexamination of Liesbergia type material should be of great interest to compare Paleogene and Jurassic specimens. Remark: The stratigraphic gap between L. liesbergensis and L. scarburghensis (Oxfordian) and L. abdounensis (Thanetian-Ypresian) may be filled, perhaps, with a systematic review of all socalled Apteodinium cysts at high magnification: presumed non-tabulate taxa often prove to be "cryptotabulate" in fact. Then, one could discover some "Apteodinium" specimens with a paratabulation pattern not belonging to Aptiana-Ventriosum Complex but to Gonyaulacysta-type, during the Cretaceous interval. Perhaps new species of Liesbergia could then be erected. Genus Spinidinium (Cookson and Eisenack) Lentin and Williams 1976
Type species: Spinidinium styloniferum Cookson and Eisenack 1962. Rakish's bore, Australia. Aptian-?Albian Spinidinium stellatum sp. nov. Holotype: Plate III, 1-3. Palynological sample and slide 16395-Z level 76, borehole SB 19, Oulad Abdoun, Morocco. England Finder references: Q 34. Paratype 1: Plate III, 5-7. Palynological sample and slide 16393-I', level 71, borehole SB 19, Oulad Abdoun, Morocco. England Finder references: Y 45-1. Paratype 2: Plate III, 8, 9. Palynological sample and slide 14402-1, level 55, borehole $4, Oulad
tml
t,m,I
t'rl
t"
335
THREE NEW DINOFLAGELLATE CYSTS FROM MOROCCO
Abdoun, Morocco. England Finder references: W 29-2. Derivation of name: stellatum: from stella (latin), in reference to the star-shaped tip of the projections Type locality: Al Borouj, Oulad Abdoun phosphate basin, Morocco Stratigraphic horizon: Thanetian, Borehole SBI9, levels 76, 74, 71, 69, 65, Thanetian to Thanetian/ Ypresian boundary, Borehole $4, levels 57, 55, 54, 51 Relative abundance: Very abundant (almost monospecific) to unfrequent Diagnosis: Rounded polygonal, compressed dorsoventrally, proximochorate two-layered cyst, circumcavate (to bicavate). Short apical horn truncated, left antapical horn variable in length, pointed, right antapical reduced or absent. Broad and laterally prominent paracingulum. Numerous projections on cyst surface, variable in length and shape complexity. Tapering proximally, with pericoele often protruding into their base; solid stem short to long, narrow to broad; distal part simple, bifurcate, trifurcate or more; at any scale, every distal extremity expanding and aculeate. Paratabulation evident (except in paracingular and parasulcal areas), peridinioid ortho- (ventral side) hexa type (dorsal side). Projections in parasutural position on ventral side, in penitabular position on
dorsal side, partially missing on 2a intercalary paraplate (border-side with 4") and on 3'" (borderside with paracingulum), absent in the paracingulum and the sulcal areas. Strong antapical dissymmetry, 2"" large and almost centered, 1"" reduced to the left antapical horn. Pedo and endo-archeopyle type Ia, eurydeltaform. Pedoperculum commonly adnate, endoperculum adnate, rarely discernible. Dimensions: holotype length: 95.5 I~m, width: 77 pm; range length: 67-116.5 llm, width: 60.5-112 I~m; processes length: 2-9.5 ~tm (homogeneous on each specimen); 120 specimens measured. Description: Spinidinium stellatum cysts are twolayered, the endophragm is thin and smooth, spheroidal, variably appressed to the periphragm (circumcavate to bicavate). The periphragm is generally smooth or shagrinate, but sometimes fove !ate (Plate IIl, 5, 6). Straight, long and simple projections are particularly well developed on the extremities of apical and antapical horn (Hate III, 4). Paracingulum borders are also prominent, underlined by more complex projections: simple, bifid or trifid, they can be linked together proxi-
PLATE III
Spinidinium stellatum sp. nov. Bar-scale 20 lam= x 500 (1-12), Bar-scale 10 l~m= x 1500 (13-14). 1-3 Holotype 1. External view/dorsal side, slide 16395-2, England Finder references Q 34, borehole SB 19, level 76. 2. Medium focus, same coordinates. 3. Internal view/ventral side, same coordinates. 4. Medium focus, slide 16393-4, E.F. ref. J 35-3, borehole SB 19, level 71. Note the adnate endoperculum. 5-7 Paratype 1. 5. External view/dorsal side, slide 16393-1", E.F. ref. Y 45-1, borehole SB 19, level 71. 6. Lower external view, same coordinates. Note the foveolate surface of the periphragm. 7. Internal view/ventral side, same coordinates. 8, 9. Paratype 2. 8. Medium focus, slide 14402-1, E.F. ref. W 29-2, borehole $4, level 55. 9. Internal view/ventral side, same coordinates Note the complexity of processes tip, discernible at low magnification. 10. External view/dorsal side, slide 16395-1, E..b. ref. S 34-I, borehole SB 19, level 76. Note the great dimensions of this specimen. I 1. Internal view/dorsal side, slide 16394-1', E.F. ref. P 33-4, borehole SB 19, level 74. Distinct dorsal hypocyst arrangement of paraplates. 12. External polar view (hypocyst), slide 16394-1', E.F. ref. P 42-4, borehole SB 19, level 74. Note the dorso-ventral compression of the cyst. 13. External view/ventral side, detail of epicyst processes tip, slide 16394-1', E.F. ref. U 37-3, borehole SB 19, level 74. 14. External view/dorsal side (hypocyst), slide 16394-1', E.F. ref. W 44-3, borehole SB 19, level 74.
336
M.-J. SONCINI
...' i f ' ; : • ~.,
R I
5 prn
~
K
v.,. , ,~
200m
3"
"., 7e ~
~' ~2";"
--
"L . . . . ~ "'~"
Fig.8. Paratabulation pattern (Kofoid notation) of Spinidinium stellatum sp. nov. reconstructed from parasutural and penitabular ornamentation. (a) external view of ventral side. (b) internal view of dorsal side.
Fig.7. Sketch drawing of varying projections features (spines, diminutive processes) observed in optical section on Spinidinium stellatum sp. nov.
genus Spinidinium, S. stellatum differs greatly from other Spinidinium species: with the penitabular and parasutural distribution of the projections (commonly covering the surface of the cyst except on pandasutural areas on other paratabulated Spinidinium species); with the complexity of these projections: short to long spines (like most Spinidinium) or diminutive processes typically expanded and aculeate (very distinctive character). Some features in S. stellatum suggest morphological affinities with the Wetzeliellaceae: processes distribution could compare with some Wilsonidium Lentin and Williams 1976, but not the ambitus (no equatorial extension for instance); distal rows of minute spines on narrow processes tip could compare with ornamentat, on on some Apectadinium (Costa and Downie) Lentin and Williams 1977, but paratabulation is generally not clear on Apectodinium cysts. However, in no case Spinidinium stellatum ~hows the characteristic quadra-type dorsal organization of the Wetzeliellaceae (2a quadra, large and broad 4"), nor the para ventral organization (/'contacts 2" and 6"). Remark: In the moroccan succession of dinocysts assemblages (Soncini, 1990), Spinidinium stellatum appears contemporaneously with a Spinidinium acme (S. aft. ?pilatum (Stanley) Costa and Downie 1979, S. densispinatum Stanley 1965, S. macmurdoense (Wilson) Lentin and Williams 1976, S. pulchrum (Benson) Lentin and Williams 1977), slightly preceeding the appearance of the Wetzeliellaceae: Apectodinium homomorphum -
mally in a discontinuous ridge. Although they are homogeneous on a single specimen, projections show a great diversity in shape and length (Fig.7); it is then hard to call them "spines" or "processes". With short or long, narrow or broad solid stem, straight or branched, bifid, trifid, they are all distally expanded and aculeate, but the rows of minute acuminate spines are hardly discernible (Plate III, 13, 14). Anyway, the first stricking feature all projections have in common is their roughly star-shaped tip (hence the species name: stellatum). Projections are scarce on paraplates surface, but numerous in parasutural position on ventral side (Plate III, 3), and in penitabular position on dorsal side (Plate III, 1, 10, 11) (rare specimens with just few "diminutive processes" underlying paratabulation). Lack of projection on posterior margin of intercalary paraplate 2a (contact 2a/u"), and on the anterior margin of postcingular paraplate 3"' (contact 3'"/paracing.) are also diagnostic features (Fig.8). Paratabulation peridinioid, with ventral ortho-type. Dorsally, la and 3a intercalaries seem to be smaller than the six-sided 2a (hexa-type). The archeopyle (type Ia) is eurydeltaform (Plate III, 1), the operculum (2a) is generally adnate (Plate III, 10). The endoperculum is also adnate and eurydeltaform, sometimes discernible inside the cyst (Plate III, 4). Comparison: Although it belongs clearly to the
-
THREE NEW DINOFLAGELLATE CYSTS FROM MOROCCO
appears 5 m higher than S. stellatum in SB 19 and 2 m higher than S. stellatum in $4 in the upper part of the Thanetian. The acme of the Wetzeliellaceae occurs le.ter, 5m above appearance of A. homomorphum in $4, in the basal Ypresian.
Conclusion The rich dinoeyst microflora from the phosphate deposits of Morocco (Oulad Abdoun basin, Phosphate Plateau) has yielded two new gonyaulacoid taxa and one new peridinioid species. Bituberieysta boroujiana gen. nov. et sp. nov. has morphological characters in common with Cordosphaeridium exilimurum but appears later, in "Ypresian deposits, where they are present together (jointly with the beginning of the ~tzeliellaceae acme). From the paratabulation pattern point of view, Bituberieysta shows close affinities with Danea and can probably be considered as a new member of the Daneagroup. Liesbergia abdounensis sp. nov. is present during Thanetian to Ypresian times. Finally, Spinidinium stellatum sp. nov. is typical of Thanetian deposits and seems to have a maximum range limited to the basal Ypresian. This abundant taxon will probably prove to be a good index species ['or Paleocene/Eocene stratigraphic boundary, slightly preceeding the index apl~ ~arance of the Wetzeliellaceae.
Acknowledgements I am indebted to the Laboratory of Palynology staff (Centre de G6ochimie de ia Surface, Strasbourg, France) for conceeding me access and use to tb,,~r microscope, computers and photographic laboratory. I wish to thank Mr. R. Rauscher who provided much helpful discussion and criticism about systematics and latin terminology. He is also gratefully acknowledged for his critical reading of the manuscript. For his helpful participation in the drawings, I also thank Mr. C. Hamel.
References Archangelsky, S. 1969. Sobre el paleomicroplancton del Terciario Inferior de Rio Turbio, Provincia de Santa Cruz. Ameghiniana, 5: 406-416. Belfkira, O., 1980. Evolutions s6dimentologiques et g~ochim-
337 iques de la s6de phosphat6e du Maastrichtien des Oulad Abdoun (Maroc). These, Univ. Scientifique M6dicale Grenoble, 164 pp. Benalioulhaj, S., 1989. Geochimie organique compar6e des s6ries du Bassin phosphat6 des Oulad Abdoun et du Bassin de schistes bitumineux de Timahdit (Maroc). Implications dans la phosphatogen6,~e. Th6se, Univ. Orl6ans, 266 pp. Berger, J.P., 1986. Dinoflagellates of the Callovian-Oxfordian boundary of the "Liesberg-Dorf'" quarry (Berner Jura, Switzerland). Neues Jahrb. Geol. Palfiontol. Abh., 172, 3: 331-355. Cookson, I. and Eisenack, A., 1962. Additional microplankton from Australian Cretaceous sediments. Micropaleontology, 8(4): 485-507. Costa, L.I. and Downie, C., 1979. The Wetzeliellaceae; Paleogene dinoflagellates. Proc. IV Inter. Palynol. Conf., Lucknow (1976-1977), 2: 34-46. Damassa, S.P., 1984. Morphologic variability and paraplate configuration of the dinoflagellate genus Danea Morgenroth 1968. Palynology, 8: 51-69. Davey, R.J., 1969. The evolution of certain Upper Cretaceous hystrichospheres from South Africa. Palaeontol. Afr., 12: 25-51. Davey, R.J., Downie, C., Sarjeant, W.A.S. and Williams, G.L., 1966. Studies on Mesozoic and Cainozoic dinoflagellate cysts. Bull. Br. Mus. Nat. Hist. Geol., Suppl. 3, 248 pp. Drugg, W.S., 1970. Some new genera, species, and combinations of phytoplankton from the Lower Tertiary of the Gulf Coast, U.S.A.N. Am. Paleontol. Conv., Chicago, 1969, Proc. G., pp.809-843. Evitt, W.R., 1985. Sporopollenin DinoflageUate Cysts, Their Morphology and Interpretation. A.A.S.P. Found., Dallas, TX, 333 pp. Helenes, J., 1986. Some variations in the paratabulation of gonyaulacoid dinoflagellates. Palynology, 10: 73-110. Lentin, J.K. and Williams, G.L., 1976. A monograph of fossil peridinioid dinoflagellate cysts. Bedford Inst. Oceanogr. Rep. Ser., BI-R-75-16: 1-237. Lentin, J.K. and Williams, G.L., 1977. Fossil dinoflagellates: Index to genera and species, 1977 edition. Bedford Inst. Oceanogr. Rep. Ser., BI-R-77-8: 1-209. Lucas-Clark, J., 1987. Vigginsiellan. gen., Spongodinium and Apteodinium as members of the Aptiana-Ventriosum Complex (fossil dinophyceae). Palynology, 11: 155-184. Rauscher, R., Soncini, M.-J., Benalioulhaj, S. and Trichet, J., 1990. Les phosphates s6dimentaires, un milieu de conservation exceptionnel de la mati6re organique. Apports de la g6ochimie organique et de la palynologie. C. R. Acad. Sci. Pads, 310, II: 613-618. Sarjeant, W.A.S., 1961. Microplankton from the Kellaways Rock and Oxford Clay of Yorkshire. Palaeontology, 4(1): 90-d 18. Sarjeant, W.A.S., 1964. New name and diagnosis for an Upper Jurassic species of Gonyaulacysta (Dinophyceae). Palaeontology, 7(3): 472-473. Sarjeant, W.A.S., 1981. A restudy of some dinoflage!late cysts holotypes in the University of Kiel Collections. II. The Eocene holotypes of Barbara Klumpp (1953); with a revision of the genus Cordosphaeridium Eisenack, 1963. Meyniana, 33:97-132.
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Sarjeant, W.A.S., 1985. The german Aptian dinoflagellate cysts of Eisenack (1958): a restudy. Rev. Palaeohot. Palynol., 45: 47-106. Soncini, M.-J., 1990. Palynologie des phosphates des Oulad Abdoua (Maroc). Biostratigraphie et environnements de la phosphatogen6se dans le cadre de la crise Cr6tac6 - - Tertiaire. These, Univ. Louis Pasteur, Strasbourg, 243 pp. Soncini, M.-J. and Rauscher, R., 1988. Associations de dinokystes du Maastrichtien-Pal6oc6ne phosphat6 au Maroc. Bull. Centres Rech. Explor.-Prod. Elf-Aquitaine, 12(1): 427-450. Soncini, M.-J. and Rauscher, R., 1990. Morphologies particu-
M.-J. $ONCINI
li6res chez les dinokystes des genres lsabelidinium, Manumiella et £,inogymnium dans les phosphates maastrichtiens et pal6oc6nes du Maroc. Bull. Centres Rech. Explor.-Prod. Elf-Aquitaine, 14(2): 583-596. Stanley, E.A., 1965. Upper Cretaceous and Paleocene plant microfossils and Paleocene dinoflagellates and hystrichosphaerids from northwestern South Dakota. Bull. Am. Paleontol., 49(222): 179-384. Stover, L.E. and Evitt, W.R., 1978. Analyses of Pre-Pleistocene organic-walled dinoflagellates. Stanford Univ. Publ. Geol. Sci., 15, 300 pp.