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Callaiosphaeridium asymmetricum ssp. asymmetricum
Callaiosphaeridium asymmetricum ssp. asymmetricum, (Deflandre and Courteville, 1939), Davey and Williams 1966
Autonym, Originally Hystrichosphaeridium, subsequently (and now) Callaiosphaeridium, thirdly Hexasphaera.
Clarke and Verdier, 1967, emended the species when they transferred it to Hexasphaera Clarke and Verdier, 1967.
Holotype: Deflandre and Courteville, 1939, pl.4, fig.1
Locality: Quarry at Marcoing, Departement du Nord, France
Age: Senonian
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Original description as Hystrichosphaeridium asymmetricum: [Deflandre and Courtville 1939, p. 100-101]: (Translation: LPP):
Diagnosis:
The brown, spheroidal shell bears six radiating, tubular appendices around the equator, often unequal in diameter as well as in length. These processes are widened at their distal ends, which are finely denticulate and bear several quite long flexible spines. At the two poles there are two roughly pentagonal fields, unequal, bearing solid, furcate processes at the corners, of very diverse form. These processes unite at their bases to form ridges or ribs which define the polar field, then producing more or less distinct meridian crests, which seem to reach the opposite polar field, as follows from the semi- schematical drawing (however, drawing given under reserve). One of the meridian ribs seems to bear, towards the equatorial plane, a simple or furcate, straight or bent process, visible on the left side of the aforementioned drawing. Some of the polar processes may be lacking (like in the holotype, where here are only 4); another time, however, they split in two branches, uniting towards their base.
Dimensions:
Range of Speeton Clay forms: Diameter of central body: 34-43 µm; length of cingular processes: 11-20 µm. Number of species measured: 4.
Range of Cenomanian forms: Diameter of central body: 37-58 µm; length of cingular processes: 10-32 µm. Number of species counted: 3.
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Supplemental description (annotated) as Callaiosphaeridium asymmetricum:
Davey and Williams 1966, p. 104:
Description:
An archaeopyle is usually present, formed by the loss of the portion of epitract just above the tubular cingular processes. The five postcingular processes are joined by ribs forming a pentagon from which radiate ribs to the cingular processes. Along one of these ribs are usually situated two processes - one posterior intercalary and one sulcal. The apical region possesses a hexagon of 6 precingular processes and a apical process which is sometimes deeply divided and arises from the centre of the hexagon.
The reflected tabulation therefore is: 1" (-2"), ?6"", 6c, 5""", 1p, 0"""" and 0-1s.
Variation: Barremian form tend to be considerably less spinous and more globular (i.e. small spaces between the endophragm and the periphragm) than Cenomanian forms. In many of the British examples, the elevation of the ribs joining the hypotractal processes forms quite well developed septa.
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Emended description as Hexasphaera assymetrica :
Clarke and Verdier, 1967, p. 43-44:
Description:
Main body more or less circular in outline, probably originally spherical.
Tabulation distinct.
The apical and antapical plates bear at each corner a solid slender process which is openly bifurcate at the extremity. A ledge connects each process; the ledge is smooth at the top but may contain perforations, especially at the base. Six large, hollow, tubular appendages are present around the equator (reflecting perhaps a girdle). These are long and expanded distally from which recurved filaments project (see text-fig. 17). The disposition of these large processes with regard to the three large plates is such that each plate has one process in the centre and half a process at its junction with the next plate, i.e. three processes are situated on the sutures and three are centra-tabular (see pl. 7, figs. 1,2). The sutures separating the large plates are frequently perforate giving a "beaded" appearance and can often be seen to extend onto three of the large processes.
Archaeopyle formed by the loss of the apical plate. Generally the amount of buckling seen in most specimens precludes a clear observation of this feature.
Autonym, Originally Hystrichosphaeridium, subsequently (and now) Callaiosphaeridium, thirdly Hexasphaera.
Clarke and Verdier, 1967, emended the species when they transferred it to Hexasphaera Clarke and Verdier, 1967.
Holotype: Deflandre and Courteville, 1939, pl.4, fig.1
Locality: Quarry at Marcoing, Departement du Nord, France
Age: Senonian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description as Hystrichosphaeridium asymmetricum: [Deflandre and Courtville 1939, p. 100-101]: (Translation: LPP):
Diagnosis:
The brown, spheroidal shell bears six radiating, tubular appendices around the equator, often unequal in diameter as well as in length. These processes are widened at their distal ends, which are finely denticulate and bear several quite long flexible spines. At the two poles there are two roughly pentagonal fields, unequal, bearing solid, furcate processes at the corners, of very diverse form. These processes unite at their bases to form ridges or ribs which define the polar field, then producing more or less distinct meridian crests, which seem to reach the opposite polar field, as follows from the semi- schematical drawing (however, drawing given under reserve). One of the meridian ribs seems to bear, towards the equatorial plane, a simple or furcate, straight or bent process, visible on the left side of the aforementioned drawing. Some of the polar processes may be lacking (like in the holotype, where here are only 4); another time, however, they split in two branches, uniting towards their base.
Dimensions:
Range of Speeton Clay forms: Diameter of central body: 34-43 µm; length of cingular processes: 11-20 µm. Number of species measured: 4.
Range of Cenomanian forms: Diameter of central body: 37-58 µm; length of cingular processes: 10-32 µm. Number of species counted: 3.
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Supplemental description (annotated) as Callaiosphaeridium asymmetricum:
Davey and Williams 1966, p. 104:
Description:
An archaeopyle is usually present, formed by the loss of the portion of epitract just above the tubular cingular processes. The five postcingular processes are joined by ribs forming a pentagon from which radiate ribs to the cingular processes. Along one of these ribs are usually situated two processes - one posterior intercalary and one sulcal. The apical region possesses a hexagon of 6 precingular processes and a apical process which is sometimes deeply divided and arises from the centre of the hexagon.
The reflected tabulation therefore is: 1" (-2"), ?6"", 6c, 5""", 1p, 0"""" and 0-1s.
Variation: Barremian form tend to be considerably less spinous and more globular (i.e. small spaces between the endophragm and the periphragm) than Cenomanian forms. In many of the British examples, the elevation of the ribs joining the hypotractal processes forms quite well developed septa.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended description as Hexasphaera assymetrica :
Clarke and Verdier, 1967, p. 43-44:
Description:
Main body more or less circular in outline, probably originally spherical.
Tabulation distinct.
The apical and antapical plates bear at each corner a solid slender process which is openly bifurcate at the extremity. A ledge connects each process; the ledge is smooth at the top but may contain perforations, especially at the base. Six large, hollow, tubular appendages are present around the equator (reflecting perhaps a girdle). These are long and expanded distally from which recurved filaments project (see text-fig. 17). The disposition of these large processes with regard to the three large plates is such that each plate has one process in the centre and half a process at its junction with the next plate, i.e. three processes are situated on the sutures and three are centra-tabular (see pl. 7, figs. 1,2). The sutures separating the large plates are frequently perforate giving a "beaded" appearance and can often be seen to extend onto three of the large processes.
Archaeopyle formed by the loss of the apical plate. Generally the amount of buckling seen in most specimens precludes a clear observation of this feature.