pforams@mikrotax - Morozovella crater pforams@mikrotax - Morozovella crater

Morozovella crater

Classification: pf_cenozoic -> Truncorotaloididae -> Morozovella -> Morozovella crater
Sister taxa: M. caucasica, M. crater, M. aragonensis, M. lensiformis ⟩⟨ M. marginodentata, M. formosa, M. gracilis, M. subbotinae, M. aequa, M. apanthesma ⟩⟨ M. edgari, M. allisonensis, M. acuta, M. occlusa, M. acutispira, M. pasionensis, M. velascoensis, M. conicotruncata, M. angulata, M. praeangulata, M. sp.


Citation: Morozovella crater (Finlay 1939)
taxonomic rank: Species
Basionym: Globorotalia crater Finlay 1939
Taxonomic discussion: NB. The discussion below has been corrected from that given in Berggren & Pearson (2006) since they incorrectly stated that G. crater was nomen nudum until Hornibrook (1958) illustrate the holotype. In fact illustration of a holotype is only mandatory under the ICZN for taxa described after 1999 and Finlay's original description was valid. [editor's comment, JR Young 2017]

Orue-Etxebarria et al. (2014) argue for separation of M. gorrondatxensis as separate species from M. crater.

In erecting the new species Globorotalia crater Finlay (1939a) gave a brief description but no formal illustration(s).  Specimens figured by Finlay (1939b, pl. 29: figs. 157, 162, 163) are from older strata than the type level and are of a different species (Hornibrook, 1958). The first proper clarification of M. crater is by Hornibrook (1958, p. 33, pl. 1, figs. 3-5) in which the holotype specimen is illustrated and a more thorough description given; see also Berggren, 1977, (p. 245, 246). Jenkins (1971, p. 103) and Blow (1979, p. 996) have presented extensive discussion of this taxon and suggested that it is either a junior synonym (Jenkins, 1971) or a pene-contemporaneous homeomorph (Blow, 1979) of M. formosa. We have found in the course of our work that crater exhibits a general test shape closer to that of aragonensis (subcircular, weakly lobulate periphery) than formosa (moderately to strongly lobulate periphery and early vorticiform spiral intercameral sutures). [Berggren & Pearson 2006]

Catalog entries: Globorotalia crater, Globorotalia aragonensis twisselmanni, Globorotalia (Morozovella) gorrondatxensis

Type images:

Distinguishing features:
Parent taxon (Morozovella): Test typically plano-convex, chambers strongly anguloconical.
Wall strongly pustulose (muricate) on parts of spire and umbilicus. Most species with muricocarina.

This taxon: Intermediate between M. lensiformis and M. caucasica - 4½ to 5 essentially equidimensional chambers in last whorl, thickened circumumbilical rim of elevated chamber shoulders, strongly limbate sutures on spiral side.

NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus.
They are being edited as the site is developed and comments on them are especially welcome.


Plano-convex test with lobulate outline, ornamented with well developed muricocarina; 4½ to 5 essentially equidimensional chambers in last whorl; umbilical intercameral sutures weakly curved to radial; sutures on spiral side curved, limbate, heavily ornamented (beaded); umbilicus deep and relatively wide, rimmed by everted, thickened circumumbilical rim of elevated chamber shoulders (tips); in edge view distinctly plano-convex.; aperture a low, interiomarginal, umbilical-extraumbilical slit with thin lip. [Berggren & Pearson 2006]

Wall type:
Muricate, nonspinose, normal perforate. [Berggren & Pearson 2006]

Maximum diameter of holotype: 0.53 mm (Jenkins, 1971, p. 104). [Berggren & Pearson 2006]

Character matrix
test outline:Lobatechamber arrangement:Trochospiraledge view:Planoconvexaperture:Umbilical-extraumbilical
sp chamber shape:Crescenticcoiling axis:Highperiphery:Muricocarinateaperture border:Thin lip
umb chbr shape:Subtriangularumbilicus:Wideperiph margin shape:Subangularaccessory apertures:None
spiral sutures:Raised muricateumb depth:Deepwall texture:Moderately muricateshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Raised muricatefinal-whorl chambers:4.5-5 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution

Widely distributed in (sub)tropical areas of Atlantic, Mediterranean/ Tethyan, Pacific Oceans and austral regions. [Berggren & Pearson 2006]
Aze et al. 2011 summary: Low latitudes; based on Berggren & Pearson (2006)

Isotope paleobiology
No data available. [Berggren & Pearson 2006]
Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts; based on comparison with other species of the genus.

Phylogenetic relations
This form evolved from M. lensiformis and evolved into M. caucasica. [Berggren & Pearson 2006]

Most likely ancestor: Morozovella lensiformis - at confidence level 4 (out of 5). Data source: Berggren & Pearson (2006) f11.1.
Likely descendants: Morozovella caucasica; plot with descendants

Biostratigraphic distribution

Geological Range:
Notes: Zone E4 to Zone E9. [Berggren & Pearson 2006]
Last occurrence (top): in upper part of E9 zone (70% up, 43.4Ma, in Lutetian stage). Data source: Berggren & Pearson (2006) f11.1
First occurrence (base): in lower part of E4 zone (40% up, 53.8Ma, in Ypresian stage). Data source: Berggren & Pearson (2006) f11.1

Plot of occurrence data:

Primary source for this page: Berggren & Pearson 2006 - Eocene Atlas, chap. 11, p. 358


Berggren, W. A. & Pearson, P. N. (2006a). Taxonomy, biostratigraphy, and phylogeny of Eocene Morozovella. In, Pearson, P. N., Olsson, R. K., Hemleben, C., Huber, B. T. & Berggren, W. A. (eds) Atlas of Eocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication . 41(Chap 11): 343-376. gs O

Berggren, W. A. (1977a). Atlas of Palaeogene Planktonic Foraminifera: some Species of the Genera Subbotina, Planorotalites, Morozovella, Acarinina and Truncorotaloides. In, Ramsay, A. T. S. (ed.) Oceanic Micropaleontology. Academic Press, London 205-300. gs

Blow, W. H. (1979). The Cainozoic Globigerinida: A study of the morphology, taxonomy, evolutionary relationships and stratigraphical distribution of some Globigerinida (mainly Globigerinacea). E. J. Brill, Leiden. 2: 1-1413. gs

Finlay, H. J. (1939b). New Zealand foraminifera: Key species in stratigraphy - no. 2. Transactions of the Royal Society of New Zealand. 69(1): 89-128. gs

Hornibrook, N. d. B. (1958). New Zealand Upper Cretaceous and Tertiary foraminiferal zones and some overseas correlations. Micropaleontology. 4: 25-38. gs

Jenkins, D. G. (1971). New Zealand Cenozoic Planktonic Foraminifera. New Zealand Geological Survey, Paleontological Bulletin. 42: 1-278. gs

Mallory, V. S. (1959). Lower Tertiary biostratigraphy of the California Coast Ranges. American Association of Petroleum Geologists, Tulsa, Oklahoma. 1-416. gs

Orue-Etxebarria, X. (1985a). Descripcion de dos nuevas especies de foraminiferos planctonicos en el Eoceno costero de la Provincia de Bizkaia. Revista Española de Micropaleontología. 17(3): 467-477. gs

Orue-Etxebarria, X., Payros, A., Caballero, F., Apellaniz, E., Pujalte, V. & Ortiz, S. (2014). Morozovella gorrondatxensis (Orue-Etxebarria 1985) vs M. crater (Hornibrook 1958): taxonomy and significance for Early/Middle Eocene boundary biostratigraphy. Stratigraphy. 11(2): 173-183. gs

Pearson, P. N. et al. (2004). Paleogene and Cretaceous sediment cores from the Kilwa and Lindi areas of coastal Tanzania: Tanzania Drilling Project Sites 1–5. Journal of African Earth Sciences. 39: 25-62. gs


Morozovella crater compiled by the pforams@mikrotax project team viewed: 11-12-2023

Taxon Search:
Advanced Search

Short stable page link: Go to to create a permanent copy of this page - citation notes

Add Comment

* Required information
Captcha Image
Powered by Commentics


No comments yet. Be the first!