Sphenolithus furcatolithoides


Classification: ntax_cenozoic -> Discoasterales -> Sphenolithaceae -> Sphenolithus -> S. furcatolithoides group -> Sphenolithus furcatolithoides
Sister taxa: S. cuniculus, S. furcatolithoides, S. kempii, S. perpendicularis, S. cf. S. perpendicularis, S. strigosus

Taxonomy:

Citation: Sphenolithus furcatolithoides Locker, 1967
Rank: Species
Variants: Sphenolithus furcatolithoides subsp. labradorensis Firth, 1989 - apical elements in contact for considerable length. Now regardeded as a separate species S. cuniculus Bown 2005

Distinguishing features: Spines diverge just above the base and are near-parallel in the lower part

Farinacci & Howe catalog pages: S. furcatolithoides *


Morphology: Small (base height 3.6-4.8 µm) with two long spines that are bright at 0° (dark at 45°) extending from the upper quadrants (up to 20 µm in length). Base is dark and inconspicuous at 45°.

Typified by two apical spines that extend and diverge from the upper basal quadrants but that are near-parallel in the lower, normally preserved, part. When preservation is very good, the upper part of the spines are preserved and may be near-parallel or diverge from the long axis of the sphenolith by varying amounts. Variants include small, gracile forms with near-parallel bifurcations that bend to form higher degree (>90°) bifurcations high on the spine (Pl. 11, fig. 26), and forms with upper spines that converge (Pl. 11, fig. 22). Specimens at the base of the species range at Site U1410 appear most similar to S. radians (Pl. 11, figs 14–15). [Bown & Newsam 2017]

See also: Sphenolithus cuniculus - very similar;

Search data:
TagsLITHS: nannolith-radiate, circular, cylindrical, CA: process, CROSS-POLARS: R-prominent,
MetricsLith size: 3->15µm;
Data source notes: lith height from OD and illustrated specs
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within NP16 zone (40.40-42.87Ma, top in Bartonian stage). Data source: Bown & Dunkley Jones, 2012
First occurrence (base): within NP15 zone (42.87-46.29Ma, base in Lutetian stage). Data source: Bown & Dunkley Jones, 2012

Plot of occurrence data:

References:

Bown, P. R. & Dunkley Jones, T. (2012). Calcareous nannofossils from the Paleogene equatorial Pacific (IODP Expedition 320 Sites U1331-1334). Journal of Nannoplankton Research. 32(2): 3-51. gs V O

Bown, P. R. & Newsam, C. (2017). Calcareous nannofossils from the Eocene North Atlantic Ocean (IODP Expedition 342 Sites U1403–1411). Journal of Nannoplankton Research. 37(1): 25-60. gs V O

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. gs V O

Fioroni, C., Villa, G., Persico, D. & Jovane, L. (2015). Middle Eocene-Lower Oligocene calcareous nannofossil biostratigraphy and paleoceanographic implications from Site 711 (equatorial Indian Ocean). Marine Micropaleontology. 118: 50-62. gs

Firth, J. V. (1989). Eocene and Oligocene calcareous nannofossils from the Labrador Sea, ODP Leg 105. Proceedings of the Ocean Drilling Program, Scientific Results. 105: 263-286. gs V O

Locker, S. (1967b). Neue Coccolithophoriden (Flagellata) aus dem Alttertiär Norddeutschlands. Geologie, Berlin. 16: 361-364. gs

Perch-Nielsen, K. (1971c). Elektronenmikroskopische untersuchungen an Coccolithen und verwandten Formen aus dem Eozan von Danemark. Biologiske Skrifter, Kongelige Danske Videnskabernes Selskab. 18(3): 1-76. gs

Perch-Nielsen, K. (1972b). Remarks on Late Cretaceous to Pleistocene coccoliths from the North Atlantic. Initial Reports of the Deep Sea Drilling Project. 12: 1003-1069. gs V O

Perch-Nielsen, K. (1977a). Albian to Pleistocene calcareous nannofossils from the Western South Atlantic, DSDP Leg 39. Initial Reports of the Deep Sea Drilling Project. 39: 699-823. gs V O

Self-Trail, J. (2011). Paleogene Calcareous Nannofossils of the South Dover Bridge core, Southern Maryland (USA). Journal of Nannoplankton Research. 32(1): 1-28. gs V O

Varol, O. (1998). Palaeogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 200-224. gs

Wise, S. W. (1983). Mesozoic and Cenozoic calcareous nannofossils recovered by DSDP Leg 71 in the Falkland Plateau region, Southwest Atlantic Ocean. Initial Reports of the Deep Sea Drilling Project. 71: 481-550. gs V O


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Sphenolithus furcatolithoides compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 15-5-2021

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1299 Go to Archive.is to create a permanent copy of this page - citation notes



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