Ceratolithus armatus

Classification: ntax_cenozoic -> Nannolith families inc sed -> Ceratolithaceae -> Ceratolithus -> Ceratolithus armatus
Sister taxa: C. cristatus, C. nishidae ⟩⟨ C. apiculus, C. armatus, C. atlanticus, C. larrymayeri, C. separatus, C. sp.


Citation: Ceratolithus armatus Muller, 1974
Rank: Species
Variants: Blair et al. (2017) subdivide C. armatus into 4 species - C. acutus, C. armatus, C. cornulum and C. apiculus. For work on on expanded Early Pliocene sections with abundant ceratoliths this scheme may prove of value. For most work, however, it is superfluous.
Taxonomic discussion: As explained in the variants section the correct name for this taxon is C. armatus, not C. acutus.

Distinguishing features: Left arm extends into apical spur producing a triangular apical area. Right arm longer than left

Farinacci & Howe catalog pages: C. armatus * , C. acutus * , C. cornulum *

Morphology: Dentate keels on upper surfae, especially right arm. Smooth keels on lower surface. C. armatus can be confused with random debris of similar shpaes, especially when it rare and preservation is indifferent. It is important in these circumstances to confirm identification by checking that the c-axis orientation is perpendicular to the length of the nannofossil.

Search data:
TagsLITHS: nannolith-other, asymmetric, horseshoe-shaped, CROSS-POLARS: 1ou, T-prominent,
MetricsLith size: 4->9µm; Segments: 1->1;
Data source notes: lith width from illustrated specimens
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: C. armatus is normally recorded as confined to NN12. However, Blair et (2017) record the range as extending into in NN13, so caution should be used in use of the LAD. Records associated with the Messinian slaiity crisi are discussed by Popescu et al 2017
Last occurrence (top): at top of NN12 zone (100% up, 5.1Ma, in Zanclean stage). Data source: top is very close to top NN12 (Young 1998)
First occurrence (base): at base of NN12 zone (0% up, 5.6Ma, in Messinian stage). Data source: Young 1998

Plot of occurrence data:


Blair, S. A., Bergen, J. A., de Kaenel, E., Browning, E. & Boesiger, T. M. (2017). Upper Miocene-Lower Pliocene taxonomy and stratigraphy in the circum North Atlantic Basin: radiation and extinction of Amauroliths, Ceratoliths and the D. quinqueramus lineage. Journal of Nannoplankton Research. 37(2-3): 113-144. gs V O

Gartner, S. & Bukry, D. (1974). Ceratolithus acutus Gartner and Bukry n. sp. and Ceratolithus amplificus Bukry and Percival - nomenclatural clarification. Tulane Studies in Geology and Paleontology. 11: 115-118. gs V O

Müller, C. (1974b). Calcareous nannoplankton, Leg 25 (Western Indian Ocean). Initial Reports of the Deep Sea Drilling Project. 25: 579-633. 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

Popescu, S-M., Melinte-Dobrinescu, M. C., Suc, J-P. & Do Couto, D. (2017). Ceratolithus acutus Gartner and Bukry 1974 (= C. armatus Müller 1974), calcareous nannofossil marker of the marine reflooding that terminated the Messinian salinity crisis: Comment on “Paratethyan ostracods in the Spanish Lago-Mare: More evidence for interbasinal exchange at high Mediterranean sea level” by Stoica et al., 2016. Palaeogeography Palaeoclimatology Palaeoecology. 485: 986-989. gs

Raffi, I., Backman, J. & Rio, D. (1998). Evolutionary trends of tropical calcareous nannofossils in the late Neogene. Marine Micropaleontology. 35(1): 17-41. gs

Theodoridis, S. (1984). Calcareous nannofossil biostratigraphy of the Miocene and revision of the helicoliths and discoasters. Utrecht Micropaleontological Bulletin. 32: 1-271. gs V O

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


Ceratolithus armatus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 25-1-2021

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=251 Go to Archive.is to create a permanent copy of this page - citation notes

Comments (1)

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Arindam Chakraborty (Lucknow, India)

If C. armatus has two months priority than C. acutus then why in the Standard Zonation chart in mikrotax.org mentions C. acutus. Same applies for C. cristatus as C. rugosus is the over grown form of C. cristatus (Bergen 1984).

Please let me know which must be used as per the nannotax database.

This is really a hard thing to combine in a biostrat table.

Jeremy Young (Tonbridge, UK)

Hi Arindam

The reason for this discrepancy is that the chart is taken straight form TimeScaleCreator not created by me and there is some bad taxonomy still on the chart - will add a note to the chart page. Almost everyone now agrees C. rugosus is junior synonym of C. cristatus so i woulstronly advise never house that name. C. acutus vs C. armatus is more controversial as some people argue that they are dslightly different morphotypes - if you only use one name you should of course use C. armatus.


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