Reticulofenestra dictyoda

Classification: Coccolithophores -> Isochrysidales -> Noelaerhabdaceae -> Reticulofenestra -> R. umbilicus group -> Reticulofenestra dictyoda
Sister taxa: R. umbilicus, R. dictyoda, R. hillae, R. hampdenensis, R. hesslandii, R. moorei, R. circus, R. circus var. lata, R. wadeae, R. maceria Shafik 1989, R. oamaruensis,

Short diagnosis: Small to very large (3-14 µm), elliptical reticulofenestrids with open central area spanned by net


Citation: Reticulofenestra dictyoda (Deflandre in Deflandre & Fert, 1954) Stradner in Stradner & Edwards, 1968
Rank: Species
Basionym: Discolithus dictyodus Deflandre in Deflandre & Fert, 1954
Synonyms: Arguably
Notes & discussion: There is much morphological variability within this group, including degree of ellipticity/circularity, size of central area and width of tube cycle. A broad species concept is often applied.
In the Neogene the name R. pseudoumbilicus is used in the virtually same sense and can appear essentially identical.

Farinacci & Howe catalog pages: Apertapetra samodurovi * Coccolithus coenurus * Discolithus dictyodus * Reticulofenestra caucasica * Reticulofenestra clatrata * Reticulofenestra donghaiensis * Reticulofenestra insignita *

Short diagnosis: Small to very large (3-14 µm), elliptical reticulofenestrids with open central area spanned by net

Size: Holotype length 5.6-6.6 microns

Search data:
TagsLITHS: placolith, elliptical, CA: grill, vacant,
CSPH: spherical, monomorphic, V-UNITS: none, R-UNITS: all, c-str, distal shield, prox shield, tube, DETAILS: ca_conjunct, isogyres kinked, isogyres oblique, rim-unicyclic,
MetricsLith size: 3->14µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within Oligocene Epoch (23.03-33.89Ma, top in Chattian stage). Data source: [JRY rough estimate]
First occurrence (base): within NP13 zone (49.11-50.50Ma, base in Ypresian stage). Data source: Perch-Nielsen 1985

Plot of occurrence data:


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

Hay, W.W.; Mohler, H.P.; Roth, P.H.; Schmidt, R.R. & Boudreaux, J.E., (1967). Calcareous nannoplankton zonation of the Cenozoic of the Gulf Coast and Caribbean-Antillean area, and transoceanic correlation. Transactions of the Gulf Coast Association of Geological Societies, 17: 428-480.

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

Müller, C., (1970). Nannoplankton-Zonen der Unteren-Meeresmolasse Bayerns. Geologica Bavarica, 63: 107-118.

Perch-Nielsen, K., (1985). Cenozoic calcareous nannofossils. In: Bolli, H.M., Saunders, J.B. and Perch-Nielsen, K. (Editors), Plankton Stratigraphy. Cambridge University Press, Cambridge, pp. 427-555.

Reinhardt, P., (1966). Fossile Vertreter coronoider und styloider Coccolithen (Family Coccolithaceae Poche 1913). Monatsberichte der Deutschen Akademie der Wissenschaften zu Berlin, 8: 513-524.

Roth, P.H., (1970). Oligocene calcareous nannoplankton biostratigraphy. Eclogae Geologicae Helvetiae, 63: 799-881.

Stradner, H. & Edwards, A.R., (1968). Electron microscopic studies on Upper Eocene coccoliths from the Oamaru Diatomite, New Zealand. Jahrbuch der Geologischen Bundesanstalt, 13(66): 1-48.

Wang, C. & Huang, W., (1989). Calcareous nannofossils., Cenozoic Paleobiota of the Continental Shelf of the East China Sea (Donghai). Micropaleobotanical Vol. Geol. Pub. House, Beijing, pp. 202-252.


Reticulofenestra dictyoda compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 15-12-2017

Taxon Search:
Advanced Search

Go to to create a permanent copy of this page - citation notes

Comments (1)

Sort By
Page 1 of 1
Simun Ascic (Zagreb University, Croatia)
Isn't here more similarity between R. dictyoda and R. hillae? R. hillae is smaller than R. umbilica.
Mike Styzen (Noble Energy, US)
As I conceptualize it, R. hillae bears the same relationship to R. umbilicus as R. gelida does to R. pseudoumbilicus. I've always chalked them up as probable environmental variants of the same species. I keep doingit because I figure that someday it might mean something, and I don't want to have to go back and split them out later.
Paul Bown (Univeristy College London, UK)
R. hillae was described as ranging from 14-20?m, so the same as R. umbilicus. There has been quite some discussion about whether R. hillae and R. umbilica are separate taxa, e.g. see Backman & Hermelin (1986).
AH Oman
I agree MIke, same size, same age range, just smaller central area. Perch-Nielsen, (1985) made the same comment about separating out R. gelida from R. pseudoumbilica. True, it may be environmental, but with some possibly stratigraphically useful exceptions, R. gelida seems to dominate the larger Retics from at least N5 up to the Late Mio Retic. pseudo/gelida acme point in lower N17. Art Waterman
Page 1 of 1

Add Comment

* Required information
Captcha Image
Powered by Commentics