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Cleistosphaeridium parvum
Cleistosphaeridium parvum, Davey, 1969
Tax. jr. synonym of Diacrocanthidium echinulatum (Deflandre, 1937) Loeblich Jr. and Loeblich III, 1970, according to Bujak in Bujak et al., 1980.
Holotype: Davey, 1969, pl. 7, fig.11
Locus typicus: Escalles, France
Stratum typicum: Cenomanian
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Original description: Davey, 1969, p. 157
Diagnosis:
Shell ovoidal, small; shell wall smooth, bearing numerous long, fine spines. Spines may be aligned along upper and lower boundaries of cingulum. Cingulum strongly laevo-rotatory.
Apical archaeopyle typically developed.
Description:
The spines are long, very fine, terminate distally in a point and widen only slightly when joining the shell. The cingulum is not always observable but some alignment of the spines parallel to the archaeopyle margin is usually present.
Dimensions:
length of central body 11-14 µm, width 10-13 µm, length of processes 6-12 µm.
Affinities:
C. parvum resembles only one previously described species, that is Palaeostomocystis echinulata Deflandre (I937) from the Upper Cretaceous of France. This species differs in that there are fewer spines (c. 12), but is similar in its ovoidal shape, apical archaeopyle, cingulum and small size (6-7 µm long).
The presence of a cingulum has not previously been observed in members of Cleistossphaeridium and might later be used as a character in generic subdivision.
Tax. jr. synonym of Diacrocanthidium echinulatum (Deflandre, 1937) Loeblich Jr. and Loeblich III, 1970, according to Bujak in Bujak et al., 1980.
Holotype: Davey, 1969, pl. 7, fig.11
Locus typicus: Escalles, France
Stratum typicum: Cenomanian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: Davey, 1969, p. 157
Diagnosis:
Shell ovoidal, small; shell wall smooth, bearing numerous long, fine spines. Spines may be aligned along upper and lower boundaries of cingulum. Cingulum strongly laevo-rotatory.
Apical archaeopyle typically developed.
Description:
The spines are long, very fine, terminate distally in a point and widen only slightly when joining the shell. The cingulum is not always observable but some alignment of the spines parallel to the archaeopyle margin is usually present.
Dimensions:
length of central body 11-14 µm, width 10-13 µm, length of processes 6-12 µm.
Affinities:
C. parvum resembles only one previously described species, that is Palaeostomocystis echinulata Deflandre (I937) from the Upper Cretaceous of France. This species differs in that there are fewer spines (c. 12), but is similar in its ovoidal shape, apical archaeopyle, cingulum and small size (6-7 µm long).
The presence of a cingulum has not previously been observed in members of Cleistossphaeridium and might later be used as a character in generic subdivision.