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Ectosphaeropsis burdigalensis
Ectospharopsis burdigalensis Londeix and Jan du Chêne, 1988
Holotype: Londeix and Jan du Chêne, 1988,pl.1, figs.1-5
Paratypes: Londeix and Jan du Chêne, 1988
Locus typicus: La Gravette excavation, Martillac, S of Bordeaux, France
Stratum typicum: Early Miocene (Burdigalian)
Translation Londeix and Jan du Chêne, 1988: LPP
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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.
Ectosphaeropsis burdigalensis Londeix and Jan du Chêne, 1988. For description see genus. Size: overall length 63-114 µm, width 42-81 µm, endocyst length 26-52 µm, width 23-47 µm, length of processes, other than at the apex 17-22um, length of apical processes 18-41 µm.
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Original description: Londeix and Jan du Chêne 1988, p. 253
Diagnosis: hercotabulate spiniferate cyst; the wall consists of a closely appressed endophragm and periphragm. The periphragm develops the exclusively gonal processes, supporting a double trabeculate network which forms the framework of a thin ectophragm. This ectophragm is smooth and fenestrate, and completely surrounds the cyst. A long and complex apical process gives the cyst a particularly elongate appearance.
Description: spiniferate cyst with a subspherical to ellipsoidal central body. The wall consists of a smooth endophragm and periphragm, closely appressed except at the positions of the processes, which are exclusively formed by the periphragm. The processes are gonal (occasionally intergonal), smooth, subcylindrical, hollow, distally open and branched; generally trifurcate and then bifurcate. Every branche is lengthened by a trabecule interconnecting the processes and forming the framework of a thin, smooth and irregularly fenestrate ectophragm, which surrounds the cyst completely. The thus formed trabeculate network is parasutural and double, of the same type as Nematosphaeropsis. An apical process distinguishes itself clearly by iits complexity, its size and especially by its length which approaches the equatorial diameter of the central body, giving the cyst a very elongate appearance. This process furcates several times lengthways, especially distally, suggesting the presence of small preapical paraplates. The antapical processes have a larger shaft than the other processes. The processes are proximally connected by septa only in polar and paracingular positions. The endophragm is delicate and very often shows a weak protruberance below the apical process.
The tabulation is gonyaulacoid: 2pr, 3', 6'', xs, 6''', 1p, 1''''. 1' may be considered as occupying the position of 1' and 4', since the limit between these two paraplates is not expressed. 6'' is reduced and triangular. 1''' is not expressed. 1'''' seems symmetrical. The archaeopyle is precingular, P(3''), with a single free operculum.
Remarks: The paratabulation has been established from paratype 5, on which the arrangement of the processes is particularly clear. The paratabulation has been deduced from the projection of the trabecules on the cyst between the bases of the processes. We remark that very small parasutural folds could sometimes be observed between the processes on the periphragm.
Dimensions:
Holotype: total length 112 Ám, endocyst length 52 Ám, process length (except apical) 22-25 Ám, apical process length 41 Ám, height of apical protruberance (endophragm) 2.5 Ám, total diameter 64 Ám, endocyst diameter 39 Ám.
Variation: total length 63(93)114 Ám, endocyst length 26(44)52 Ám, process length (except apical) 17-22 Ám, apical process length 18(32)41 Ám, total diameter 42(56)81 Ám, endocyst diameter 23(36)47 Ám.
Affinities:
Londeix and Jan du Chêne 1988, p. 253, 255, 257
Spiniferites paradoxus (Cookson and Eisenack, 1968) Sarjeant, 1970, with its elongate ambitus, may, at first sight, be mistaken for Ectosphaeropsis burdigalensis, since the two species possess a considerable cavation, and apical process which is longer than the other processes and an apical protruberance formed by the endophragm. However, the cavation in S. paradoxus does not entirely envelop the central body and is situated between endophragm and periphragm, delimiting a pericoel, whereas in Ectosphaeropsis there is an ectocoel.
Spiniferites cornutus (Gerlach, 1961) Sarjeant, 1970 possesses a prominent apical horn, but neither a trabecular network, nor an ectophragm.
Hystrichostrogylon holohymenium Islam, 1983 is characterized by a cavation which completely surrounds the central body, which, however, delimits a pericoel, not an ectocoel. Furthermore, H. holohymenium does not have a differentiated apical process.
The trabecular network of E. burdigalensis appears similar to that of Nematosphaeropsis labyrinthea (Ostenfeld, 1903) Reid, 1974, but the latter species poossesses neither an apical horn nor an ectophragm.
Cannosphaeropsis franciscana Damassa, 1979, presents an apical projection and a trabecular network, although the latter is simple and does not support an ectophragm.
Holotype: Londeix and Jan du Chêne, 1988,pl.1, figs.1-5
Paratypes: Londeix and Jan du Chêne, 1988
Locus typicus: La Gravette excavation, Martillac, S of Bordeaux, France
Stratum typicum: Early Miocene (Burdigalian)
Translation Londeix and Jan du Chêne, 1988: LPP
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Ectosphaeropsis burdigalensis Londeix and Jan du Chêne, 1988. For description see genus. Size: overall length 63-114 µm, width 42-81 µm, endocyst length 26-52 µm, width 23-47 µm, length of processes, other than at the apex 17-22um, length of apical processes 18-41 µm.
--------------------------------------------------
Original description: Londeix and Jan du Chêne 1988, p. 253
Diagnosis: hercotabulate spiniferate cyst; the wall consists of a closely appressed endophragm and periphragm. The periphragm develops the exclusively gonal processes, supporting a double trabeculate network which forms the framework of a thin ectophragm. This ectophragm is smooth and fenestrate, and completely surrounds the cyst. A long and complex apical process gives the cyst a particularly elongate appearance.
Description: spiniferate cyst with a subspherical to ellipsoidal central body. The wall consists of a smooth endophragm and periphragm, closely appressed except at the positions of the processes, which are exclusively formed by the periphragm. The processes are gonal (occasionally intergonal), smooth, subcylindrical, hollow, distally open and branched; generally trifurcate and then bifurcate. Every branche is lengthened by a trabecule interconnecting the processes and forming the framework of a thin, smooth and irregularly fenestrate ectophragm, which surrounds the cyst completely. The thus formed trabeculate network is parasutural and double, of the same type as Nematosphaeropsis. An apical process distinguishes itself clearly by iits complexity, its size and especially by its length which approaches the equatorial diameter of the central body, giving the cyst a very elongate appearance. This process furcates several times lengthways, especially distally, suggesting the presence of small preapical paraplates. The antapical processes have a larger shaft than the other processes. The processes are proximally connected by septa only in polar and paracingular positions. The endophragm is delicate and very often shows a weak protruberance below the apical process.
The tabulation is gonyaulacoid: 2pr, 3', 6'', xs, 6''', 1p, 1''''. 1' may be considered as occupying the position of 1' and 4', since the limit between these two paraplates is not expressed. 6'' is reduced and triangular. 1''' is not expressed. 1'''' seems symmetrical. The archaeopyle is precingular, P(3''), with a single free operculum.
Remarks: The paratabulation has been established from paratype 5, on which the arrangement of the processes is particularly clear. The paratabulation has been deduced from the projection of the trabecules on the cyst between the bases of the processes. We remark that very small parasutural folds could sometimes be observed between the processes on the periphragm.
Dimensions:
Holotype: total length 112 Ám, endocyst length 52 Ám, process length (except apical) 22-25 Ám, apical process length 41 Ám, height of apical protruberance (endophragm) 2.5 Ám, total diameter 64 Ám, endocyst diameter 39 Ám.
Variation: total length 63(93)114 Ám, endocyst length 26(44)52 Ám, process length (except apical) 17-22 Ám, apical process length 18(32)41 Ám, total diameter 42(56)81 Ám, endocyst diameter 23(36)47 Ám.
Affinities:
Londeix and Jan du Chêne 1988, p. 253, 255, 257
Spiniferites paradoxus (Cookson and Eisenack, 1968) Sarjeant, 1970, with its elongate ambitus, may, at first sight, be mistaken for Ectosphaeropsis burdigalensis, since the two species possess a considerable cavation, and apical process which is longer than the other processes and an apical protruberance formed by the endophragm. However, the cavation in S. paradoxus does not entirely envelop the central body and is situated between endophragm and periphragm, delimiting a pericoel, whereas in Ectosphaeropsis there is an ectocoel.
Spiniferites cornutus (Gerlach, 1961) Sarjeant, 1970 possesses a prominent apical horn, but neither a trabecular network, nor an ectophragm.
Hystrichostrogylon holohymenium Islam, 1983 is characterized by a cavation which completely surrounds the central body, which, however, delimits a pericoel, not an ectocoel. Furthermore, H. holohymenium does not have a differentiated apical process.
The trabecular network of E. burdigalensis appears similar to that of Nematosphaeropsis labyrinthea (Ostenfeld, 1903) Reid, 1974, but the latter species poossesses neither an apical horn nor an ectophragm.
Cannosphaeropsis franciscana Damassa, 1979, presents an apical projection and a trabecular network, although the latter is simple and does not support an ectophragm.