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Brigantedinium auranteum
Brigantedinium auranteum, Reid, 1977, ex Lentin and Williams, 1993
This species name was not validly published in Reid, 1977, since the generic name Brigantedinium was not validly published at that time.
Holotype: Reid, 1977, pl.1, fig.1
Occurrence: Found in small numbers in nearly all samples from the British Isles.
Age: Recent
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Original description: [Reid, 1977]:
Diagnosis:
Spherical smooth cysts with a thick hyaline wall and a thin closely attached and frequently crumpled inner wall.
Archeopyle largely subhexagonal, its longest axis up to three-fifths of the cyst diameter with a length/breath ratio of 1:1.
Description:
The periphragm of this species may be pale yellow or colorless and hyaline in appearance. The overall pale brown color of the cyst is a reflection through this transparent colorless layer from the thon closely attached membraneous endophragm. This brown inner layer may be slightly detached and folded to give a crenulate surface with shallow depressions, like a lunar landscape. If the endophragm becomes detached from the periphragm it usually remains in contact along the archeopyle suture. In well-preserved specimens the archeopyle has the appearance of being surrounded by hyaline collar, which in reality is a reflection of the oblique nature of the archeopyle suture and the thickness of the wall. One specimen was pierced by two narrow ores though both the inner and outer walls with pads of tissue (which accept safranin stain) at the internal and external openings. Similar pads were noted on copepod eggs, and are probably caused by chitrid fungal attack.
Dimensions:
Holotype: Test 49 X 52 µm, Archeopyle 30 µm, Wall thickness 1.6 µm.
Range: Test diameter 42 X 40 – 58 X 63 µm, Archeopyle 26 X 26 – 30 X 30 µm, Wall thickness 1-2.5 µm. Number of species measured 15.
Remarks:
The state of preservation of this species varies greatly. Both highly crumpled and unaltered specimens with little or no crumpling of the inner layer may be found in the same sample. This implies that variation in preservation is not caused by preparation techniques, but is a diagenetic effect or is caused by variation in the strength of the cysts when first formed within the thecal stage.
Affinities:
The archeopyle shape of this species is most comparable to that of the cyst of Protoperidinium conicoides (Paulsen) Balech; Wall and Dale (1968) pl. 2, fig. 29, (B. simplex sp. nov.). It differs from this species in the pale color of the test wall and the lack of compression and from previously described species in not having a laterally elongate archeopyle. Its thecal affinity is not yet clear.
This species name was not validly published in Reid, 1977, since the generic name Brigantedinium was not validly published at that time.
Holotype: Reid, 1977, pl.1, fig.1
Occurrence: Found in small numbers in nearly all samples from the British Isles.
Age: Recent
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Reid, 1977]:
Diagnosis:
Spherical smooth cysts with a thick hyaline wall and a thin closely attached and frequently crumpled inner wall.
Archeopyle largely subhexagonal, its longest axis up to three-fifths of the cyst diameter with a length/breath ratio of 1:1.
Description:
The periphragm of this species may be pale yellow or colorless and hyaline in appearance. The overall pale brown color of the cyst is a reflection through this transparent colorless layer from the thon closely attached membraneous endophragm. This brown inner layer may be slightly detached and folded to give a crenulate surface with shallow depressions, like a lunar landscape. If the endophragm becomes detached from the periphragm it usually remains in contact along the archeopyle suture. In well-preserved specimens the archeopyle has the appearance of being surrounded by hyaline collar, which in reality is a reflection of the oblique nature of the archeopyle suture and the thickness of the wall. One specimen was pierced by two narrow ores though both the inner and outer walls with pads of tissue (which accept safranin stain) at the internal and external openings. Similar pads were noted on copepod eggs, and are probably caused by chitrid fungal attack.
Dimensions:
Holotype: Test 49 X 52 µm, Archeopyle 30 µm, Wall thickness 1.6 µm.
Range: Test diameter 42 X 40 – 58 X 63 µm, Archeopyle 26 X 26 – 30 X 30 µm, Wall thickness 1-2.5 µm. Number of species measured 15.
Remarks:
The state of preservation of this species varies greatly. Both highly crumpled and unaltered specimens with little or no crumpling of the inner layer may be found in the same sample. This implies that variation in preservation is not caused by preparation techniques, but is a diagenetic effect or is caused by variation in the strength of the cysts when first formed within the thecal stage.
Affinities:
The archeopyle shape of this species is most comparable to that of the cyst of Protoperidinium conicoides (Paulsen) Balech; Wall and Dale (1968) pl. 2, fig. 29, (B. simplex sp. nov.). It differs from this species in the pale color of the test wall and the lack of compression and from previously described species in not having a laterally elongate archeopyle. Its thecal affinity is not yet clear.