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Hystrichosphaeridium salpingophorum

Hystrichosphaeridium salpingophorum (Deflandre, 1935) Deflandre, 1937; emend. Davey and Williams, 1966

Originally Hystrichosphaera, subsequently (and now) Hystrichosphaeridium.
Holotype: Deflandre, 1935, pl.9, fig.1
Age: Senonian

Translation Gocht, 1969: Geological Survey of Canada

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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 salpingophorum Deflandre, 1935 ex Deflandre, 1937b, emend. Davey and Williams, 1966b. According to Davey and Williams (1966b, 62), Hystrichosphaeridium salpingophorum has a spheroidal to ovoidal central body with characteristic reflected tabulation of 4', 6", 6c, 5"’, 1p, 1"” with a variable number of sulcal processes. Processes well developed, tubiform, with subquadrate distal openings. Distal margins entire or denticulate. Number of processes present 25-30. In the London Clay forms, the distal openings of the processes may be up to 18 µm wide. Medially the processes rarely exceed 10 µm and are usually much less. The wall of the processes is slightly fibrous. The distal margin can be serrate, undulose or even aculeate. Processes may be perforate distally. Size: diameter of central body 35-40 µm, length of processes 25-30 µm. Size of London Clay material: diameter of central body 30-44 µm, process length 14-20 µm.
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Original description (Deflandre, 1935) Not yet translated from French.
H. salpinophora à coque sphérique ou subspérique ornée de processus tubulaires plus ou moins évasés.

Emended diagnosis: Davey and Willliams 1966, p. 61-62
Central body spherical to ovoidal with characteristic reflected tabulation of 4', 6",6c, 5"', 1p, 1"" with variable number of sulcal processes. Processes well developed, tubiform, with sub-quadrate distal openings. Distal margins entire or denticulate. Number of processess present 25 to 30. Apical tetratabular archaeopyle practically always present.

Description: Davey and Willliams 1966, p. 61-62
The surface of the central body may be smooth or slightly granular, and composed of two layers, the endophragm and periphragm (absent beneath the processes). The processes expand gradually towards the distal sub-quadrate opening, which is up to 18µ across in the London Clay forms. Medially the processes rarely exceed 10Á and are usually much less. The wall of the processes (composed of periphragm) is slightly fibrous. The distal margin can be serrate, undulose or even aculeate. Processes may be perforate distally.

Dimensions: Range of specimens from type material (Deflandre I937); diameter of central body 35 to 40Á, length of processes 25 to 30µ, the number of processes is approximately 30. Range of London Clay specimens: diameter of central body 30-44µ length of processes 14-20µ. Number of specimens measured, 4.

Remarks: The London Clay specimens have rather short and broader processes than the holotype and are perhaps a variety of H. salpingophorum. The ribs, illustrated by Klement (Ig60), extending along the length of the processes and running into the central body have not been observed. The specimen figured by Lejeune-Carpentier (Ig40, text-fig. 8) is very similar to the London Clay forms. H. salpingophorum (London Clay) is generally easi]y distinguished from H. tubiferum. However certain specimens from the London Clay are transitional, often showing the circle formed at the junction of the processes and the endophragm. A close relationship with H. tubiferltm is also indicated by the identical tabulation and intratabular processes. The Jurassic forms formerly attributed to H. salpingophorltm are transferred below to Hystrichosphaeridium costatl6m sp. nov.
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Gocht, 1969, p.52:
Hystrichosphaeridium cf. salpingophorum Deflandre, 1937
The delicate globose body is compressed. It exhibits approximately 27 tubular processes which are slightly widened at the distal end and barely widened at the proximal end. The distal ends have jagged edges or are drawn into short cusps. The shafts are mounted directly on the main body, and delimit oval fields. Individual processes are long and thin. On one side, there is an indistinct opening with torn edges. The only specimen found resembles the one illustrated by Davey and Williams, which is directly identified with H. salpingophorum (Davey and Williams, 1966).
Measurements: Maximal extension 116 µ, main body diameter 59: 57 µ.
Occurrence: Paleocene.

Supplementary remark: A few smaller specimens, which are also compressed, have fewer processes. Judging by their external appearance, they are reminiscent of H. tubiferum (Ehrenberg). A definite determination is not possible. (Paleocene and Early Eocene.)
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