Morozovelloides lehneri


Classification: pf_cenozoic -> Truncorotaloididae -> Morozovelloides -> Morozovelloides lehneri
Sister taxa: M. lehneri, M. coronatus, M. crassatus, M. bandyi, M. sp.,

Taxonomy

Citation: Morozovelloides lehneri (Cushman & Jarvis 1929)
Rank: Species
Basionym: Globorotalia lehneri
Synonyms:
Taxonomic discussion: The holotype of Morozovelloides lehneri is illustrated by SEM for the first time on Pl. 10.4, Figs. 1-3. It is not a very well-preserved specimen but it shows the key morphological features of the taxon. With its smooth, translucent (when well preserved) elongate-petaloid test, radially elongate chambers and blade-like to fimbriate muricocarina, this is one of the most distinctive of the Eocene species. We use it to typify the new genus Morozovelloides.
Blow (1979, p. 1002) pointed to the phylogenetic trend observed in this morphotype of a gradual enlargement of the umbilicus and ontogenetic disruption/discontinuity in the peripheral muricocarina in younger/later chambers of the final whorl, which may be of stratigraphic utility. In our investigation of well-preserved populations from Tanzania, we have observed a recurrent morphotype with chevron-pointed chamber ends (see Plate 10.4, Fig. 15) but it is unclear whether this variety is of stratigraphic utility. [Pearson & Berggren 2006]

Catalog entries: Globorotalia lehneri

Type images:

Distinguishing features: Test biconvex, very thin; chambers elongate, wedge-shaped; surface smooth except for blade-like to fimbriate peripheral muricocarina. Grades into M. coronatus in the lower part of its range, but has more elongate and more numerous chambers

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.

Description


Diagnostic characters: Characterized by its low-biconvex, very thin, and essentially smooth, glossy test, its elongate, wedge-shaped chambers, straight to weakly curved, radial sutures on both the umbilical and spiral sides, and distinct blade-like to fimbriate peripheral muricocarina. It grades into Morozovelloides coronatus in the lower part of its range, where it is distinguished by the more elongate and more numberous chambers and tendency for crowding of the last one or two chambers. [Pearson & Berggren 2006]

Wall type: Muricate, normal perforate, with concentrations of muricae around periphery and umbilicus and largely smooth chamber surfaces in between. [Pearson & Berggren 2006]

Test morphology: Low trochospiral, low biconvex elongate-oval, strongly lobulate, normal perforate; early chambers muricate, later chambers essentially smooth, with scattered muricae around umbilical region; chambers weakly inflated, compressed; distinct blade-like or fimbriate peripheral muricocarina; 5-9 radially elongate, slightly inflated subtriangular to wedge-shaped chambers on umbilical side, flattening towards peripheral margin; intercameral sutures weakly curved on early portion of final whorl, essentially straight, radial and depressed on later part; umbilicus closed to narrowly open (in older forms), uniformly open and shallow in younger forms, rimmed by elevated circumumbilical chamber tips; aperture a low, umbilical extraumbilical slit extending to periphery; approximately 12-14 chambers arranged in 2½ to 3 whorls (early chambers often obscured by muricae); sutures depressed; periphery rimmed with a thick, blade-like to fimbriate muricocarina which, in the younger/later part of the test exhibits a tendency to become discontinuous; in edge view low biconvex trochospire, ante penultimate chambers gently sloping, raised circumumbilical tips of earlier chambers of last whorl projecting outwards [Pearson & Berggren 2006]

Size: Holotype: 0.36 mm; thickness/width: 0.15 mm (Cushman and Jarvis, 1929, p. 17). [Pearson & Berggren 2006]

Character matrix

test outline:Stellatechamber arrangement:Trochospiraledge view:Compressedaperture:Umbilical-extraumbilical
sp chamber shape:Subtriangularcoiling axis:Lowperiphery:Muricocarinateaperture border:N/A
umb chbr shape:Subtriangularumbilicus:Narrowperiph margin shape:Subangularaccessory apertures:None
spiral sutures:Weakly depressedumb depth:Shallowwall texture:Moderately muricateshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Weakly depressedfinal-whorl chambers:5.0-9.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Cosmopolitan in the tropics and subtropics. [Pearson & Berggren 2006]
Aze et al. 2011 summary: Low latitudes; based on Pearson & Berggren (2006)

Isotope paleobiology: Morozovelloides lehneri has consistent oxygen and carbon isotopic ratios indicative of a shallow mixed layer habitat (Boersma and others, 1987; Pearson and others, 2001). [Pearson & Berggren 2006]
Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts. Based on very heavy δ13C and relatively light δ18O. Sources cited by Aze et al. 2011 (appendix S3): Boersma et al. (1987); Pearson et al. ( 2007)

Phylogenetic relations: This morphotype evolved from Morozovelloides coronatus in the early middle Eocene by radial elongation of the chambers, further compression of the test and development of a thickened, blade-like and/or fimbriate muricocarina. [Pearson & Berggren 2006]

Most likely ancestor: Morozovelloides coronatus - at confidence level 4 (out of 5). Data source: Pearson & Berggren 2006, f10.1.

Biostratigraphic distribution

Geological Range:
Notes: Uppermost Zone E8-E12. [Pearson & Berggren 2006] NB Given the problems with zones E7 and E8 disccussed by Wade et al. 2100 the FAD may need revising [JRY 2017]
Last occurrence (top): within E12 zone (39.97-40.40Ma, top in Bartonian stage). Data source: Pearson & Berggren 2006, f10.1
First occurrence (base): in upper part of E8 zone (80% up, 44.2Ma, in Lutetian stage). Data source: Pearson & Berggren 2006, f10.1

Plot of occurrence data:

Primary source for this page: Pearson & Berggren 2006 - Eocene Atlas, chap. 10, p. 338

References:

Bermudez, P. J. (1949). Tertiary smaller foraminifera of the Dominican Republic. Cushman Laboratory for Foraminiferal Research, Special Publication. 25: 1-322. gs :: ::

Bermudez, P. J. (1961). Contribucion al estudio de las Globigerinidea de la region Caribe-Antillana (Paleoceno-Reciente). Editorial Sucre, Caracas. 1119-1393. gs :: ::

Blow, W. H. (1969). Late middle Eocene to Recent planktonic foraminiferal biostratigraphy. In, Bronnimann, P. & Renz, H. H. (eds) Proceedings of the First International Conference on Planktonic Microfossils, Geneva, 1967. E J Brill, Leiden 380-381. 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 :: ::

Boersma, A., Premoli Silva, I. & Shackleton, N. J. (1987). Atlantic Eocene planktonic foraminiferal paleohydrographic indicators and stable isotope paleoceanography. Paleoceanography. 2: 287-331. gs :: ::

Bolli, H. M. (1957a). Planktonic foraminifera from the Eocene Navet and San Fernando formations of Trinidad. In, Loeblich, A. R. , Jr. , Tappan, H. , Beckmann, J. P. , Bolli, H. M. , Montanaro Gallitelli, E. & Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin. 215: 155-172. gs :: ::

Cushman, J. A. & Jarvis, P. W. (1929). New foraminifera from Trinidad. Contributions from the Cushman Laboratory for Foraminiferal Research. 5: 6-17. gs :: ::

Hofker, J. (1962). Änderung des Generationswechsels der Foraminiferen-Arten Während des Periods ihres dasiens. Neues Jahrbuch für Geologie und Palaeontologie Monatshefte. 8: 316-329. gs :: ::

Pearson, P. N. & Berggren, W. A. (2006). Taxonomy, biostratigraphy, and phylogeny of Morozovelloides n. gen. 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 10): 327-342. gs :: ::

Pearson, P. N. et al. (2001a). Warm tropical sea surface temperatures in the Late Cretaceous and Eocene epochs. Nature. 413: 481-487. gs :: ::

Postuma, J. A. (1971). Manual of planktonic foraminifera. Elsevier for Shell Group, The Hague. 1-406. gs :: ::

Samuel, O. (1972a). New species of planktonic foraminifers from the Paleogene of the West Carpathians in Slovakia (Czechoslovakia). Zborník geologických vied, séria Západné Karpaty. 17: 217-221. gs :: ::

Toumarkine, M. & Luterbacher, H. (1985). Paleocene and Eocene planktic foraminifera. In, Bolli, H. M. , Saunders, J. B. & Perch-Neilsen, K. (eds) Plankton Stratigraphy. Cambridge Univ. Press, Cambridge 87-154. gs :: ::

Toumarkine, M. (1975). Middle and Late Eocene planktonic foraminifera from the northwestern Pacific Ocean: Leg 32 of the Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project. 32: 735-751. gs :: ::


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Morozovelloides lehneri compiled by the pforams@mikrotax project team viewed: 2-6-2020

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