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Hystrichosphaeridium arborispinum
Hystrichosphaeridium arborispinum Davey and Williams, 1966
Holotype: Davey and Williams, 1966, pl. 9, figs. 5, 10
Locus typicus: Speeton Clay, Yorkshire, England
Stratum typicum: Early-Middle Barremian
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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.
Hystrichosphaeridium arborispinum Davey and Williams, 1966b. According to Davey and Williams (1966b, p.61), Hystrichosphaeridium arborispinum has a subspherical to ovoidal central body with granular or reticulate wall. Processes hollow, tubiform, usually simple, expanding distally and terminating with complicated secate margin. The distal margins of the processes have a distinctly ragged appearance due to the irregular shape of the secae-some being irregularly lobate, others giving off spines laterally. Some specimens have fibrous and fenestrate processes. Number of processes is 23 to 24. Size: diameter of central body 31-43 µm, process length 10-23 µm.
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Original diagnosis: Davey and Williams, 1966, p. 55-56
Sub-spherical to ovoidal central body composed of thin endophragm and granular or reticulate periphragm. Processes, composed of periphragm, hollow, tubiform, usually simple, expanding distally and terminating with complicated secate margin. Apical archaeopyle commonly present.
Original description: Davey and Williams, 1966, p. 56
The distal extremities of the processes have a distinctive ragged appearance due to the irregular shape of the secae--some being irregularly lobate, others giving off spines laterally. Specimens with vibrous processes, and more rarely with fenestrate processes, have been observed. An apical archaeopyle commonly seems to be present, but its precise nature is difficult to determine for the specimens are extremely thin walled and easily distorted. The number of processes seems to be standardized at 22 to 23, and this together with their arrangement on the surface of the central body indicate that H. arborispinum sp. nov. has a reflected tabulation similar to that of H. tubiferum.
Holotype: Davey and Williams, 1966, pl. 9, figs. 5, 10
Locus typicus: Speeton Clay, Yorkshire, England
Stratum typicum: Early-Middle Barremian
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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.
Hystrichosphaeridium arborispinum Davey and Williams, 1966b. According to Davey and Williams (1966b, p.61), Hystrichosphaeridium arborispinum has a subspherical to ovoidal central body with granular or reticulate wall. Processes hollow, tubiform, usually simple, expanding distally and terminating with complicated secate margin. The distal margins of the processes have a distinctly ragged appearance due to the irregular shape of the secae-some being irregularly lobate, others giving off spines laterally. Some specimens have fibrous and fenestrate processes. Number of processes is 23 to 24. Size: diameter of central body 31-43 µm, process length 10-23 µm.
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Original diagnosis: Davey and Williams, 1966, p. 55-56
Sub-spherical to ovoidal central body composed of thin endophragm and granular or reticulate periphragm. Processes, composed of periphragm, hollow, tubiform, usually simple, expanding distally and terminating with complicated secate margin. Apical archaeopyle commonly present.
Original description: Davey and Williams, 1966, p. 56
The distal extremities of the processes have a distinctive ragged appearance due to the irregular shape of the secae--some being irregularly lobate, others giving off spines laterally. Specimens with vibrous processes, and more rarely with fenestrate processes, have been observed. An apical archaeopyle commonly seems to be present, but its precise nature is difficult to determine for the specimens are extremely thin walled and easily distorted. The number of processes seems to be standardized at 22 to 23, and this together with their arrangement on the surface of the central body indicate that H. arborispinum sp. nov. has a reflected tabulation similar to that of H. tubiferum.