pforams@mikrotax - Morozovelloides crassatus

Citation: Morozovelloides crassatus (Cushman 1925)

Basionym: Pulvinulina crassata crassatus

Synonyms:

Pulvinulina crassata Cushman, 1925:300, pl. 7: fig. 4 [Eocene, Moctezuma River, Mexico].
Globorotalia crassata (Cushman).—Cole, 1927:34, pl. 1: figs. 7-8 [middle Eocene Guayabal Fm., Mexico].—Howe, 1939:84, 85, pl. 12: figs. 7-9 [middle Eocene, Cook Mountain Fm., Louisiana].—Cushman and Applin, 1943:44, pl. 8: fig. 10a-b [middle Eocene, Yegua Fm., Texas].—Cushman and Renz, 1946:40, pl. 8: figs. 5-6 [middle Eocene, Navet Fm., Trinidad].—Saito, 1962:214, pl. 33: figs. 3a-4c [middle Eocene, Haha-Jima, Bonin Islands, western Pacific Ocean].—Bandy, 1964:34, 35, fig. 1a-c (lectotype selected and illustrated) [Eocene, Mexico].
?Pulvinulina crassata Cushman var. densa Cushman, 1925, p. 300 [lower middle Eocene, east bank Moctezuma River, Vera Cruz, Mexico].
Globorotalia spinulosa Cushman, 1927:114, pl. 23: figs. 4a-c [middle Eocene “Alazan Clays” (but more likely Guayabal Fm.; see Blow, 1979:1015), Rio Tuxpam, Vera Cruz, Mexico].—Howe, 1939:85, pl. 12: figs. 10-12 [middle Eocene, Cook Mountain Fm., Louisiana].— Pessagno, 1961:356, pl. 2: figs. 11-13 [middle Eocene, Jacaguas Group, Puerto Rico.—Aubert, 1963:61, 62, pl. 4: figs. 4a-c [middle Eocene, Jebel Si- Ameur-el-Hadi, Basra Valley, Morocco]. —Postuma, 1971:212, figs. on p. 213 [middle Eocene, Trinidad].
Pseudogloborotalia spinulosa (Cushman).—Bermúdez 1961:1347, pl.17: figs. 2a, b [middle Eocene, Oriente Province, Cuba].
Morozovella spinulosa (Cushman).—Poore and Bybell, 1988:18, pl. 5: figs. 4. 5 [Turborotalia possagnoensis Zone, Shark River Fm., ACGS No. 4 borehole, Atlantic County, New Jersey].—Toumarkine and Luterbacher, 1985:130, 131 (partim), figs. 30.1 (holotype refigured), 4-8 [middle Eocene Orbulinoides beckmanni Zone, Navet Fm., Trinidad].
Globorotalia (Morozovella) spinulosa (Cushman).—Blow, 1979:1012-1015, pl. 182: figs. 1-3 [Zone P11, DSDP Site 21A, South Atlantic Ocean]; pl. 197: figs. 1-6 [Zone P13, Kilwa area, Tanzania]; pl. 229: figs. 1-4; pl. 240: figs. 1-4 [Zone P14, Lindi area, Tanzania]; see also pl. 168, fig. 9 [Zone P11, Kilwa area, Tanzania].
Globorotalia hadii Aubert, 1963:62, pl. 4: figs. 1-3 [Jebel Si-Ameur-el-Hadi, Basra Valley, Morocco].
Not Globorotalia crassata (Cushman). —Subbotina, 1953, pl. 17: figs. 7a-13c [=various species].
Not Globorotalia spinulosa (Cushman).—Saito, 1962:215, pl. 33: figs. 9a-c [middle Eocene, Ha-Ha-Jima, Bonin Islands, Western Pacific Ocean] [ =Morozovelloides coronatus].

Taxonomic discussion: Originally described as crassata, the ending has been changed to agree in gender with the genus Morozovelloides (ICZN, Art. 32.1). Morozovelloides crassatus and its synonym spinulosa have been recognized many times in the literature. They have been lumped by some authors and split by others, and have frequently been confused with lower Eocene morozovellids. The holotypes of both crassatus and spinulosa are illustrated here in SEM for the first time. Both are poorly preserved specimens with (apparently) about 4½ chambers in the final whorl. Both come from the middle Eocene of Mexico. The illustration of the lectotype of crassata selected by Bandy (1964) is highly misleading and should not be used to form a taxonomic judgment of this species. The taxonomic vicissitudes of M. crassatus may be summarized as follows:
1. Cushman (1925) named Pulvinulina crassata and Pulvinulina crassata var. densa from the middle Eocene of Mexico. Two years later he also named Globorotalia spinulosa from the Eocene of Mexico (Cushman, 1927). The type series of all these species are poorly preserved and the original illustrations are unsatisfactory by modern standards. Nevertheless, many authors have reported finding these species in subsequent investigations in various parts of the world.
2. Bandy (1964) erected and described a lectotype (USNM 3026) for Pulvinulina crassata Cushman from a syntypic series in the Cushman collections. Unfortunately, he was apparently misled by earlier, incorrect references to crassatus in giving the taxon a stratigraphic range of upper Paleocene through middle Eocene and suggesting phylogenetic affinities intermediate between G. angulata and G. rex.
3. Blow (1969, p. 370) subsequently stated that he had studied the types of crassatus (as lectotypified) and spinulosa at the USNM and found them to be synonymous, but different from the hypotypes described by Bolli (1957b) from Trinidad as G. spinulosa. He drew attention to the fact that a new taxon would subsequently be described for G. spinulosa of Bolli (1957b) by himself and one of us (WAB). This paper was never written; Blow died in 1972, but the taxon coronatus appeared in his posthumous work (Blow, 1979) (see Morozovelloides coronatus, this paper).
4. In his posthumously published work, Blow (1979, p. 1012) reported that Bandy’s lectotype of crassatus was missing from the USNM (during a visit in 1970) and stated his opinion that the remaining syntypes were not conspecific with Bandy’s lectotype illustration of crassatus (although Bandy [1964] had stated that “most of the syntypes of Globorotalia crassata agree very closely with the specimen selected and designated the lectotype herein”). In view of the tedious procedure of having to invoke the plenary powers of International Commission for Zoological Nomenclature to suppress the lectotype of Pulvinulina crassata Cushman (inasmuch as the figures were still available), before a neotype could be erected from the syntypic series still remaining at the USNM, Blow (1979, p. 1012) recommended that crassatus should be considered nomen dubium non conservandum and the subsequently named spinulosa should be retained since
among the specimens in the syntypic series of crassatus there are individuals which conform to Cushman’s subsequent description of spinulosa. These arguments of Blow (1979) are rendered superfluous by the subsequent rediscovery of the crassatus lectotype.
Given the poor preservation of the types of crassatus and spinulosa (particularly the former), and their complex taxonomic histories, we have found it difficult to recommend clear guidelines for their discrimination that do not merely add to the taxonomic confusion. The most conservative solution is to follow Banner and Blow (1960) and Berggren (1977) in regarding crassatus as a senior synonym of spinulosa, while at the same time acknowledging that other solutions would be equally consistent with the known facts given the poor and probably broken condition of the crassatus lectotype.
Finally, mention needs to be made of Pulvinulina crassata var. densa Cushman 1925, also from the Moctezuma River in Mexico. This taxon has been variously recognized as a “morozovellid” (for example, as a more highly vaulted variant of crassatus) or an acarininid (similar to, and perhaps synonymous with, A. bullbrooki). Our new SEM illustrations of the holotype suggest that the former solution is more likely to be true. However, it is an atypical morphology for the middle Eocene, and we do not attempt to separate highly vaulted Morozovelloides from the more usual, biconvex morphologies in our taxonomy, hence it is held in questionable synonymy with crassatus. [Pearson & Berggren 2006]

Distinguishing features:
Parent taxon (Morozovelloides): Like Morozovella, but derived from Acarinina.
This taxon: Test asymmetrically low-biconvex, sometimes nearly planoconvex; umbilicus closed to narrow

Description

An asymmetrically low-biconvex test with closed or small, deep and narrow umbilicus, sometimes nearly planoconvex; differs from coronatus in lacking the strongy muricate circumumbilical ‘coronet’ and in having a closed to narrow umbilicus and from lehneri in its umbilico-convex test and thicker and more densely muricate keel and fewer chambers in the final whorl. [Pearson & Berggren 2006]

Biogeography and Palaeobiology

Widely distributed in (sub)tropical regions of the world (see citations above); not recorded from the North Caucasus. [Pearson & Berggren 2006]
Aze et al. 2011 summary: Low latitudes; based on Pearson & Berggren (2006)

Oxygen and carbon isotopic ratios indicative of a shallow water, photosymbiotic habitat (Boersma and others, 1987, Pearson and others, 1993, 2001, Wade and others, 2001, Wade and Kroon, 2002; all recorded as Morozovella spinulosa). This interpretation is supported by the boron isotope data of Pearson and Palmer (1999) (also recorded as M. spinulosa). [Pearson & Berggren 2006]
Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts. Based on very heavy _¹³C and relatively light _¹⁸O. Sources cited by Aze et al. 2011 (appendix S3): Boersma et al. (1987); Pearson et al. (1993, 2001a); Wade et al. (2001); Wade & Kroon (2002); Wade et al. (2008)

Morozovelloides crassatus evolved from M. bandyi and gave rise to M. coronatus. [Pearson & Berggren 2006]

Biostratigraphic distribution

Geological Range:
Notes: Zone E8-13 (middle Eocene; see Wade (2004) for data on the last occurrence).
[Pearson & Berggren 2006]
NB Given the problems with zones E7 and E8 disccussed by Wade et al. 2100 this range may need revising [JRY 2017] The LAD of Morozovelloides crassatus marks the base of zone E14 / top of E13 (Wade et al. 2011)
Last occurrence (top): at top of E13 zone (100% up, 38Ma, in Bartonian stage). Data source: zonal marker (Wade et al. 2011)
First occurrence (base): within E7b subzone (45.72-48.31Ma, base in Ypresian stage). Data source: Pearson & Berggren 2006, f10.1

Primary source for this page: Pearson & Berggren 2006 - Eocene Atlas, chap. 10, p. 332

References:

Bandy, O. L. (1964). Cenozoic planktonic foraminiferal zonation. Micropaleontology. 10: 1-17. gs

Banner, F. T. & Blow, W. H. (1960a). Some primary types of species belonging to the superfamily Globigerinaceae. Contributions from the Cushman Foundation for Foraminiferal Research. 11: 1-41. gs O

Bermudez, P. J. (1961). Contribucion al estudio de las Globigerinidea de la region Caribe-Antillana (Paleoceno-Reciente). Editorial Sucre, Caracas. (3): 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

Cole, W. S. (1927). A foraminiferal fauna from the Guayabal formation in Mexico. Bulletins of American Paleontology. 14(51): 1-36. gs

Cushman, J. A. & Applin, E. R. (1943). The foraminifera of the type locality of the Yegua Formation of Texas. Contributions from the Cushman Laboratory for Foraminiferal Research. 19(2): 28-46. gs

Cushman, J. A. & Renz, H. H. (1946). The foraminiferal fauna of the Lizard Springs formation of Trinidad, British West Indies. Cushman Laboratory for Foraminiferal Research, Special Publication. 18: 1-48. gs

Cushman, J. A. (1925b). An Eocene fauna from the Moctezuma River, Mexico. Bulletin of the American Association of Petroleum Geologists. 9(2): 298-301. gs

Cushman, J. A. (1927b). New and interesting foraminifera from Mexico and Texas. Contributions from the Cushman Laboratory for Foraminiferal Research. 3(2): 111-119. gs

Howe, H. V. (1939). Louisiana Cook Mountain Eocene foraminifera. Bulletin of the Geological Survey of Louisiana. 14: 1-122. 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 O

Pearson, P. N. & Palmer, M. R. (1999). Middle Eocene seawater pH and atmospheric carbon dioxide concentrations. Science. 284: 1824-1826. gs

Pearson, P. N., Shackleton, N. J. & Hall, M. A. (1993). Stable isotope paleoecology of middle Eocene planktonic foraminifera and multi-species isotope stratigraphy, DSDP Site 523, South Atlantic. Journal of Foraminiferal Research. 23: 123-140. gs

Pessagno, E. A. (1961). The micropaleontology and biostratigraphy of the middle Eocene Jacaguas group, Puerto Rico. Micropaleontology. 7(3): 351-358. gs

Poore, R. Z. & Bybell, L. M. (1988). Eocene to Miocene biostratigraphy of New Jersey Core ACGS #4: Implications for regional stratigraphy. U.S. Geological Survey Bulletin. 1829: 1-41. gs

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

Saito, T. (1962a). Eocene planktonic foraminifera from Hahajima (Hillsborough Island). Transactions and Proceedings of the Palaeontological Society of Japan. 45: 209-225. 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

Wade, B. S. & Kroon, D. (2002). Middle Eocene regional climate instability: Evidence from the western North Atlantic. Geology. 30: 1011-1014. gs

Wade, B. S. (2004). Planktonic Foraminiferal biostratigraphy and mechanisms in the extinction of Morozovella in the Late Middle Eocene. Marine Micropaleontology. 51: 23-38. gs

Wade, B. S., Kroon, D. & Norris, R. D. (2001). Orbitally forced climate change in the Late Middle Eocene at Blake Nose (Leg 171B): Evidence From Stable Isotopes In Foraminifera. Geological Society of London, Special Publications. 183: 273-291. gs

Wade, B. S., Pearson, P. N., Berggren, W. A. & Pälike, H. (2011). Review and revision of Cenozoic tropical planktonic foraminiferal biostratigraphy and calibration to the geomagnetic polarity and astronomical time scale. Earth-Science Reviews. 104: 111-142. gs

test outline:	Subcircular	chamber arrangement:	Trochospiral	edge view:	Planoconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Inflated	coiling axis:	Low	periphery:	N/A	aperture border:	N/A
umb chbr shape:	Subtriangular	umbilicus:	Wide	periph margin shape:	Subangular	accessory apertures:	None
spiral sutures:	Weakly depressed	umb depth:	N/A	wall texture:	Moderately muricate	shell porosity:	Finely Perforate: 1-2.5µm
umbilical or test sutures:	Moderately depressed	final-whorl chambers:	5-6	N.B. These characters are used for advanced search. N/A - not applicable

Morozovelloides crassatus

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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