Caycedoa pattersonii
Set number: 595
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10µm
Holotype in mobile mount
Caycedoae pattersonii Bowman & Varol, 2021
Circular species of Caycedoa having a parallel-sided high column that appears yellowish and bluish-red in the plan view under polarised light. The column has a striated periphery and a smoother centre.
In honour of Dr William P. Patterson, professor and stable isotope geochemist at the University of Saskatchewan (Canada), and former mentor at Syracuse University (USA).
Overall height: 6.83μm; Column height: 3.63μm, Column diameter: 6.54μm; Disc diameter: 9.53μm.
Large (8.0–10.0μm) and circular species of Caycedoa consist of one disc and a parallel-sided high column. The disc is wide ( disc diameter> column diameter), with a depression on the proximal side. A narrow central canal occupies the parallel-sided high column and the disc. A similar number of segments (about 32–40) comprise the disc and column.
In the distal/column side, the extinction lines are dextrogyre, but the extinction lines are laevogyre in the proximal/disc side. When viewed using a gypsum plate, the horizontal axis appears within the blue sector on the distal side, but the vertical axis lies within the blue sector on the proximal side. In the plan view, the column appears yellowish and bluish-red (under polarised light). The disc is non-birefringent in plan-view. The disc and column are birefringent in the side-view.
Caycedoa pattersonii differs from Caycedoa conicus by having a parallel-sided column, whereas Caycedoa conicus has a column tapering distally. Moreover, the number of segments in Caycedoa pattersonii is >32, whereas in Caycedoa conicus it is <32. Caycedoa pattersonii is distinguished from Caycedoa micheliorum by having a taller column than a wider one, whereas in the latter, the column is wider than taller. In plan view, Caycedoa pattersonii displays yellowish and bluish-red birefringent colours, whereas Caycedoa micheliorum displays only yellow birefringence colour under polarised light.
Bowman, A. R. & Varol, O. 2021. A Taxonomic Revision of Heliolithaceae - Applications in Resolving the Problematic Calcareous Nannofossil Biostratigraphy of the Paleocene. In: M. Montenary, M. (Ed.). Calcareous nannofossil biostratigraphy of the Stratigraphy and timescales. 6: 43-223.
Holotype
Caycedoa pattersonii
Bowman & Varol, 2021
Late Paleocene
DSDP Leg 39, Sites 354, Ceará Rise, North Atlantic Ocean