Zygrhablithus bijugatus


Classification: ntax_cenozoic -> Holococcoliths -> fossil holococcoliths -> Zygrhablithus -> Zygrhablithus bijugatus
Sister taxa: Z. bijugatus, Z. sileensis, Z. sp.

Daughter taxa (time control age-window is: 0-800Ma)
Zygrhablithus bijugatus subsp. bijugatus
Medium to large spinose holococcoliths comprising a rim and central process; the spine has a narrow axial canal and tapers uniformally to a distal point or blunt termination.
Zygrhablithus bijugatus subsp. cornutus
Medium-sized spinose holococcolith comprising a rim and central process; the spine is relatively long, has a narrow axial canal and short lateral protrusions or horns at its distal end (two in side view).
Zygrhablithus bijugatus subsp. maximus
Z. bijugatus with tall spines (height >12 µm and ~>2x width) that display relatively low birefringence in XPL, although brighter ridges are present on most specimens.
Zygrhablithus bijugatus subsp. nolfi
Small to medium sized spinose holococcolith comprising a rim and central process; the spine is short and broad (the coccoliths are typically wider than high), has a notch just above the height of the rim, and a rather broad axial canal.

Taxonomy:

Citation: Zygrhablithus bijugatus (Deflandre in Deflandre and Fert, 1954) Deflandre, 1959
Rank: Species
Basionym: Zygolithus bijugatus Deflandre in Deflandre and Fert, 1954
Synonyms: List from Aubry (1988) Of these I. claviformis, S. enigmatica and R. semiformis were all based on isolated half or quarter specimens of Z. bijugatus. Shamrock & Watkins (2012) record similar specimens as "Nanno indet type 2", but with restricted range in the uppermost Eocene.
Also

Distinguishing features: Large rod-shaped holococcolith with small basal disk

Farinacci & Howe catalog pages: Z. bijugatus * , Zygrhablithus bijugatus, S. kerabyi * , I. claviformis * , L. dispar * , P. altus * , P. latus * , P. comprimus * , R. semiformis * , S. enigmatica * , R. costatus * , Z. bijugatus crassus *


Morphology: In well-preserved material (E.g. Bown 2005) it can be seen that these are cavate holococcoliths, i.e. they have an internal cavity. Usually however with overgrowth this cavitiy is filled and the holococcolith develops an irregular form.

Search data:
TagsLITHS: holococcolith, elliptical, hollow, CA: process, CROSS-POLARS: V-prominent, R-prominent,
MetricsLith size: 5->16µm; Segments: 5->5;
Data source notes: lith size (height) from ODs
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: This species is also rarely seen in NN2 (see de Kaenel and Villa, 1996).
Last occurrence (top): within NN1 zone (22.82-23.13Ma, top in Aquitanian stage). Data source: Young 1998
First occurrence (base): within NP9 zone (55.86-57.21Ma, base in Thanetian stage). Data source: Agnin et al. 2007

Plot of occurrence data:

References:

Aubry, M. -P. (1988a). Handbook of Cenozoic calcareous nannoplankton. Book 2: Ortholithae (Catinasters, Ceratholiths, Rhabdoliths). Micropaleontology Press, American Museum of Natural History, New York. 1-279. gs

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. (2016). Paleocene calcareous nannofossils from Tanzania (TDP sites 19, 27 and 38). Journal of Nannoplankton Research. 36(1): 1-32. gs V O

Bramlette, M. N. & Sullivan, F. R. (1961). Coccolithophorids and related nannoplankton of the Early Tertiary in California. Micropaleontology. 7(2): 129-188. gs

Brönnimann, P. & Stradner, H. (1960). Die Foraminiferen- und Discoasteriden-zonen von Kuba und ihre interkontinentale Korrelation. Erdoel-Zeitschrift. 76(10): 364-369. gs

Bybell, L. M. & Self-Trail, J. (1995). Evolutionary, biostratigraphic and taxonomic study of calcareous nanofossils from a continuous Palaeocene-Eocene boundary section in New Jersey. U.S. Geological Survey, Professional Paper. 1554: 1-36. gs V O

Bybell, L. & Self-Trail, J. (1997). Late Paleocene and Early Eocene calcareous nannofossils from three boreholes in an onshore-offshore transect from New Jersey to the Atlantic continental rise. Proceedings of the Ocean Drilling Program, Scientific Results. 150: 91-110. gs V O

Bybell, L. (1975). Middle Eocene calcareous nannofossils at Little Stave Creek, Alabama. Tulane Studies in Geology and Paleontology. 11(4): 177-247. gs V O

de Kaenel, E. & Villa, G. (1996). Oligocene-Miocene calcareous nannofossil biostratigraphy and paleoeecology from the Iberian Abyssal Plain. Proceedings of the Ocean Drilling Program, Scientific Results. 149: 79-145. gs V O

Deflandre, G. & Fert, C. (1954). Observations sur les coccolithophoridés actuels et fossiles en microscopie ordinaire et électronique. Annales de Paléontologie. 40: 115-176. gs

Deflandre, G. (1959). Sur les nannofossiles calcaires et leur systématique. Revue de Micropaléontologie. 2: 127-152. gs

Fioroni, C., Villa, G., Persico, D., Wise, S. W. & Pea, L. (2012). Revised middle Eocene-upper Oligocene calcareous nannofossil biozonation for the Southern Ocean. Revue de Micropaléontologie. 55(2): 53-70. gs

Haq, B. U. (1971). Paleogene calcareous nannoflora. Parts I-IV. Stockholm Contributions in Geology. 25: 1-158. gs

Hay, W. W., Mohler, H. P. & Wade, M. E. (1966). Calcareous nannofossils from Nal'chik (northwest Caucasus). Eclogae Geologicae Helvetiae. 59: 379-399. gs V O

Jones, A. P. & Dunkley Jones, T. (2020). Middle Eocene to Early Oligocene calcareous nannofossils from the Nanggulan Formation, Java, Indonesia. Journal of Nannoplankton Research. 30(1): 57-79. gs V O

Locker, S. (1967c). Neue, statigraphisch wichtige Coccolithophoriden (Flagellata aus dem norddeutschen Altetiar). Monatsberichte der Deutschen Akademie der Wissenschaften zu Berlin. 9(9-10): 758-769. 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

Shamrock, J. L. & Watkins, D. K. (2012). Eocene calcareous nannofossil biostratigraphy and community structure from Exmouth Plateau, Eastern Indian Ocean (ODP Site 762). Stratigraphy. 9(1): 1-11. gs

Shepherd, C. L. & Kulhanek, D. K. (2016). Eocene nannofossil biostratigraphy of the mid-Waipara River section, Canterbury Basin, New Zealand. Journal of Nannoplankton Research. 26(1): 33-59. gs V O

Stradner, H. (1961). Vorkommen von Nannofossilien im Mesozoikum und Alttertiär. Erdoel-Zeitschrift. 77(3): 77-88. gs

Young, J. R. (1998). Neogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 225-265. gs V O


nannotaxlogo400px

Zygrhablithus bijugatus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 24-2-2021

Taxon Search:
Advanced Search

Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1530 Go to Archive.is to create a permanent copy of this page - citation notes



Comments (0)

No comments yet on this page. Please do add comments if you spot any problems, or have information to share

Add Comment

* Required information
1000
Captcha Image
Powered by Commentics