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Deflandrea terrula
Deflandrea terrula Davey, 1974; Emendation: Harding, 1986a, p.101-102,104, as Subtilisphaera terrula.
Now Subtilisphaera. Originally Deflandrea, subsequently Subtilisphaera?, thirdly (and now) Subtilisphaera.
Holotype: Davey, 1974, pl.8, fig.4
Locus typicus: Speeton Clay, England
Stratum typicum: Middle Barremian
Original diagnosis: Davey, 1974, p. 65
The cyst is dorso-ventrally flattened and is composed of a subspherical inner body surrounded by a thinner outer wall. The inner body is in contact with the outer wall only in dorsal and ventral regions. The latter may have a rounded apex or may be produced into a short horn; usually only a short left antapical horn is present. A well defined peridinoid tabulation is present marked by low thickenings of the outer wall; each suture is marked either by a single ridge or two adjacent parallel ridges. The cingulum is strongly defined by granular or spiny ridges. A wide sulcal depression is present with the cingulum displaced by its own width along it. Intratabular granules and sometimes spines are present. An archeopyle has never been observed.
Dimensions: Range: cyst length: 53-88 Ám; cyst width: 37-68 Ám.
Original description: Davey, 1974, p. 65
The three anterior intercalary plates are usually visible and do not appear to be displaced and only occasionally is a breakage in the precingular or apical region observable.
Remark: D.terrula is characterised by a distinct tabulation, intratabular granules, a continuous cingulum and the absence of apical "shoulders" and an archaeopyle.
Now Subtilisphaera. Originally Deflandrea, subsequently Subtilisphaera?, thirdly (and now) Subtilisphaera.
Holotype: Davey, 1974, pl.8, fig.4
Locus typicus: Speeton Clay, England
Stratum typicum: Middle Barremian
Original diagnosis: Davey, 1974, p. 65
The cyst is dorso-ventrally flattened and is composed of a subspherical inner body surrounded by a thinner outer wall. The inner body is in contact with the outer wall only in dorsal and ventral regions. The latter may have a rounded apex or may be produced into a short horn; usually only a short left antapical horn is present. A well defined peridinoid tabulation is present marked by low thickenings of the outer wall; each suture is marked either by a single ridge or two adjacent parallel ridges. The cingulum is strongly defined by granular or spiny ridges. A wide sulcal depression is present with the cingulum displaced by its own width along it. Intratabular granules and sometimes spines are present. An archeopyle has never been observed.
Dimensions: Range: cyst length: 53-88 Ám; cyst width: 37-68 Ám.
Original description: Davey, 1974, p. 65
The three anterior intercalary plates are usually visible and do not appear to be displaced and only occasionally is a breakage in the precingular or apical region observable.
Remark: D.terrula is characterised by a distinct tabulation, intratabular granules, a continuous cingulum and the absence of apical "shoulders" and an archaeopyle.