Sphenolithus anarrhopus

Bukry & Bramlette, 1969b May 11, 2021

Set number: 944

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10µm

Sphenolithus anarrhopus, Late Paleocene, IODP Leg 171, Site 1051A, Black Nose, Western North Atlantic

Set number: 943

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10µm

Sphenolithus anarrhopus, Late Paleocene, IODP Leg 171, Site 1051A, Black Nose, Western North Atlantic

Set number: 942

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10µm

Sphenolithus anarrhopus, Late Paleocene, IODP Leg 171, Site 1051A, Black Nose, Western North Atlantic

Set number: 941

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10µm

Sphenolithus anarrhopus, Late Paleocene, DSDP Leg 25, Site 245A, Mozambique Channel (Davie Ridge), Indian Ocean

Set number: 940

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10µm

Sphenolithus anarrhopus, Late Paleocene, DSDP Leg 25, Site 245A, Mozambique Channel (Davie Ridge), Indian Ocean

Set number: 939

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10µm

Sphenolithus anarrhopus, Late Paleocene, DSDP Leg 39, Sites 354, Ceará Rise, North Atlantic Ocean

Set number: 935

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10µm

Sphenolithus anarrhopus, Late Paleocene, DSDP Leg 39, Sites 354, Ceará Rise, North Atlantic Ocean

Set number: 938

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10µm

Sphenolithus anarrhopus, Late Paleocene, DSDP Leg 39, Sites 354, Ceará Rise, North Atlantic Ocean

Set number: 936

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10µm

Sphenolithus anarrhopus, Late Paleocene, IODP Leg 171, Site 1051A, Black Nose, Western North Atlantic

Final Epithet

Sphenolithus anarrhopus Bukry & Bramlette, 1969b

Basionym

Sphenolithus anarrhopus Bukry & Bramlette, 1969b

Synonyms

Sphenolithus rioi Agnini Fornaciari & Raffi, 2008

Description

Medium size species of Sphenolithus Deflandre in Grassé (1952) has an apical spine that can be short or long but slightly asymmetrical [in a certain profile can be symmetrical]. The apical spine without axial median line display extinction at 0° and maximum birefringent at 45° (parallel extinction). The proximal and lateral cycles together are about square in shape. The lateral segments form the relatively deep calyx for the insertion of the apical spine.

Remarks

Sphenolithus anarrhopus is distinguished from Sphenolithus villae Bown (2005) and Sphenolithus conspicuus Martini (1976) by having an asymmetrical apical spine and square base (lateral and proximal cycles together].

References

Agnini, C., Fornaciari, E., Raffi, I., 2008. Three new species of calcareous nannofossil from Late Palaeocene and Early Eocene assemblages (Ocean Drilling Program Site 1262, Walvis Ridge, SE Atlantic Ocean). Journal of Nannoplankton Research 30(1), 51-56.

Bown, P. R., 2005d. Palaeogene calcareous nannofossils from the Kilwa and Lindi areas of coastal Tanzania (Tanzania Drilling Project 2003-4). Journal of Nannoplankton Research 27(1), 21-95.

Bukry, D., Bramlette, M. N., 1969b. Some new and stratigraphically useful calcareous nannofossils of the Cenozoic. Tulane Studies in Geology 7, 131-142.

Deflandre, G., 1952. Classe des Coccolithophoridés. (Coccolithophoridae. Lohmann, 1902). In: Grassé, P. P. (ed.), Traité de Zoologie. Masson, Paris 439-470.

Martini, E., 1976. Cretaceous to Recent calcareous nannoplankton from the Central Pacific Ocean (DSDP Leg 33). Initial Reports of the Deep Sea Drilling Project 33, 383-423.