Biscutum rotatorius

(Bukry, 1970) Varol, n. comb. Jan 13, 2026

Set number: 2755

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10µm

Biscutum rotatorius, Late Aptian, Arabian Peninsula (The specific location cannot be disclosed)

Set number: 2757

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10µm

Biscutum rotatorius, Middle Campanian, Arabian Peninsula (The specific location cannot be disclosed)

Set number: 2756

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10µm

Biscutum rotatorius, Middle Campanian, Arabian Peninsula (The specific location cannot be disclosed)

Set number: 2754

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10µm

Biscutum rotatorius, Middle Cenomanian, Eastern Gulf of Mexico

Final Epithet

Biscutum rotatorius (Bukry, 1970) Varol, n. comb.

Basionym

Bidiscus rotatorius Bukry, 1969

Dimensions Of Holotype

Size: 4.3 µm (coccosphere: 9.0 µm); number of segments in the distal shield: ¬20

Optical Properties

In plan view under XPL, the distal shield is in constant extinction because the optic axis (c-axis) is perpendicular to the microscope stage, whereas the proximal shield and tube cycle display a white interference colour and exhibit length-fast (–) elongation.

Remarks

The circular placolith has a distal shield larger than the proximal shield, each composed of approximately 16-30 segments, and a tube cycle.

References

Bukry, D. 1969. Upper Cretaceous coccoliths from Texas and Europe. University of Kansas Paleontological Contributions, Articles 51 (Protista 2): 1-79.

Taxonomy

Biscutum

Biostratigraphy

Stratigraphic Range

Late Aptian - Middle Campanian

Age (Ma)

118.76? - 76.38?

Holotype

Bidiscus rotatorius Bukry, 1969

Coniacian - Santonian

Knox County, Nebraska, USA