Bukrylithus ambiguus

Set number: 2855

1
2
3
4
5
6
7

10µm

Bukrylithus ambiguus, Early Cenomanian, Folkestone, England

Set number: 2856

1
2
3
4
5
6
7
8
9

10µm

Bukrylithus ambiguus, Middle Albian, Folkestone, England

Set number: 2857

1
2
3
4
5
6
7
8
9
10
11
12

10µm

Bukrylithus ambiguus, Late Albian, Folkestone, England

Set number: 2858

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

10µm

Bukrylithus ambiguus, Late Albian, Folkestone, England

Set number: 2859

1
2
3
4
5
6
7

10µm

Bukrylithus ambiguus, Late Albian, Folkestone, England

Set number: 2860

1
2
3
4
5
6
7
8

10µm

Bukrylithus ambiguus, Late Albian, Folkestone, England

Final Epithet

Bukrylithus ambiguus Black, 1971a

Basionym

Bukrylithus ambiguus Black, 1971a

Optical Properties

In plan view under XPL, the wall, axial cross, and intercross segments show constant extinction, reflecting the orientation of their optic axes (c‑axes) perpendicular to the microscope stage. The stellate distal process, in contrast, exhibits white interference colours.

Remarks

Species of Bukrylithus characterised by a massive crossbar with a distinct median suture and a distal process bearing a robust calyx. The inter‑cross areas are infilled with coarse segments. The long arm of the axial cross tapers markedly from the centre toward the wall, whereas tapering in the short arm is less pronounced. The stellate calyx of the distal process typically obscures the central area.

References

Black, M. 1971a. Coccoliths of the Speeton Clay and Sutterby Marl. Proceedings of the Yorkshire Geological Society 38: 381-424.

Taxonomy

Bukrylithus

Bukrylithus ambiguus

Biostratigraphy

Stratigraphic Range

Early Hauterivian - Early Cenomanian

Age (Ma)

132.60? - 96.24?

Holotype

Bukrylithus ambiguus Black, 1971

Hauterivian

Speeton Clay at Speeton, England