Taxon Concept provided by
  Home |   Search
 
   TaxonConcept data set details:
 
 
Back to Search
Anonymous: Unedited TaxonConcept data
Notice: This catalogue page may contain unedited data.

Species Morozovelloides crassatus Cushman 1925


Diagnosis / Definition:
Pearson et al. (2006):
DESCRIPTION. Type of wall: Muricate, especially around periphery and umbilicus, often with smooth dorsal and ventral surfaces to chambers. Test morphology: Low trochospiral, elongate-oval to subcircular, weakly to moderately lobulate periphery; generally 5 (less commonly 4 1/2 and rarely 6) chambers in last whorl; chambers on umbilical side subtriangular, weakly inflated; sutures on umbilical side depressed, radial, straight, recurving near the periphery; umbilicus closed or relatively narrow, deep, rimmed by rounded, muricate shoulders of circumumbilical confluence of chambers; primary aperture a low, umbilical-extraumbilical slit extending to the margin; on spiral side approximately 10- 12 chambers arranged in 2 1/2-3 whorls in low trochospire; chambers increase gradually in size, preantepenultimate and antepenultimate chambers often of approximately same size; last chamber variable, usually larger, but in some instances smaller ('kummerform'); chambers lens-shaped to trapezoidal as a function of strength of curvature of intercameral sutures; spiral intercameral sutures strongly recurved and distinctly muricate; in edge view asymmetrically biconvex; spiral side weakly convex, early whorl(s) slightly elevated; umbilical side distinctly convex, truncate. Size: Maximum diameter of holotype: 0.30 mm; height 0.17 mm.
Discussion / Comments:
Pearson et al. (2006):
DISTINGUISHING FEATURES.- 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 umbilicoconvex test and thicker and more densely muricate keel and fewer chambers in the final whorl. 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 4 1/2 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: l. 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 (1 957b) 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 [l9641 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 (1 979, p. 10 12) recommended that crassatus should be considered nomen dubium non consewandum 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. PHYLOGENETIC RELATIONSHIPS.- Morozovelloides crassatus evolved from M. bandyi and gave rise to M. coronatus. STRATIGRAPHIC RANGE.- Zone E8- 13 (middle Eocene; see Wade (2004) for data on the last occurrence). GEOGRAPHIC DISTRIBUTION.- Widely distributed in (sub)tropical regions of the world (see citations above); not recorded from the North Caucasus. STABLE ISOTOPE PALEOBIOL0GY.- 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 (1 999) (also recorded as M. spinulosa).
Systematics:

35
 Ordo Foraminiferida
  Superfamilia Globigerinaceae
   Familia Truncorotaloididae
    Genus Morozovelloides
     Species Morozovelloides crassatus
Synonym list:
Pearson et al. (2006):
1925 Pulvinulina crassata Cushman. - Cushman : p.300 pl. 7; fig. 4 [Eocene, Moctezuma River, Mexico]
? 1925 Pulvinulina crassata var. densa Cushman. - Cushman : p.300 [lower middle Eocene, east bank Moctezuma River, Vera Cruz, Mexico]
1927 Globorotalia crassata Cushman. - Cole : p.34 pl. 1; fig. 7-8 [middle Eocene Guayabal Fm., Mexico]
1927 Globorotalia spinulosa Cushman. - Cushman : p.114 pl. 23; fig. 4a-c [middle Eocene "Alazan Clays" (but more likely Guayabal Fm.; see Blow, 1979: 10 15), Rio Tuxpam, Vera Cruz, Mexico]
1939 Globorotalia crassata Cushman. - Howe : p. 84, 85 pl. 12; fig. 7-9 [middle Eocene, Cook Mountain Fm., Louisiana]
1939 Globorotalia spinulosa Cushman. - Howe : p.85 pl. 12; fig. 10-12 [middle Eocene, Cook Mountain Fm., Louisiana]
1943 Globorotalia crassata Cushman. - Cushman & Applin : p.44 pl. 8; fig. 10a-b [middle Eocene, Yegua Fm., Texas]
1946 Globorotalia crassata Cushman. - Cushman & Renz : p.40 pl. 8; fig. 5-6 [middle Eocene, Navet Fm., Trinidad]
non 1953 Globorotalia crassata Cushman. - Subbotina : pl. 17; fig. 7a-13c [=various species]
1961 Globorotalia spinulosa Cushman. - Pessagno : p.356 pl. 2; fig. 11-13 [middle Eocene, Jacaguas Group, Puerto Rico]
1961 Pseudogloborotalia spinulosa Cushman. - Bermudez : p.1347 pl. 17; fig. 2a, b [middle Eocene, Oriente Province, Cuba]
1962 Globorotalia crassata Cushman. - Saito : p.214 pl. 33; fig. 3a-4c [middle Eocene, Haha-Jima, Bonin Islands, western Pacific Ocean]
non 1962 Globorotalia spinulosa Cushman. - Saito : p.215 pl. 33; fig. 9a-c [middle Eocene, Ha-Ha-Jima, Bonin Islands, Western Pacific Ocean]; [=Morozovelloides coronatus]
1963 Globorotalia spinulosa Cushman. - Aubert : p. 61, 62 pl. 4; fig. 4a-c [middle Eocene, Jebel Si- Ameur-el-Hadi, Basra Valley, Morocco]
1963 Globorotalia hadii Aubert. - Aubert : p.62 pl. 4; fig. 1-3 [Jebel Si- Ameur-el-Hadi, Basra Valley, Morocco]
1964 Globorotalia crassata Cushman. - Bandy : p. 34, 35 fig. 1a-c (lectotype selected and illustrated) [Eocene, Mexico]
1971 Globorotalia spinulosa Cushman. - Postuma : p.212 fig. on p. 213 [middle Eocene, Trinidad]
1979 Globorotalia (Morozovella) spinulosa Cushman. - Blow : p. 1012-1015 pl. 182, fig. 1-3[Zone P1 1, DSDP Site 21A, South Atlantic Ocean]; pl. 197, fig. 1-6 [Zone P13, Kilwa area, Tanzania]; pl. 229, fig. 1-4; pl. 240, fig. 1-4 [Zone P14, Lindi area, Tanzania]; see also pl. 168, fig. 9 [Zone P1 1, Kilwa area, Tanzania]
p 1985 Morozovella spinulosa Cushman. - Toumarkine & Luterbacher : p. 130, 131 fig. 30.1 (holotype refigured), 4-8 [middle Eocene Orbulinoides beckmanni Zone, Navet Fm., Trinidad]
1988 Morozovella spinulosa Cushman. - Poore & Bybell : p.18 pl. 5; fig. 4, 5 [Turborotalia possagnoensis Zone, Shark River Fm., ACGS No. 4 borehole, Atlantic County, New Jersey]
2006 Morozovelloides crassatus Cushman. - Pearson et al. : p.337 pl. 10.3; fig. 1-16 (PI. 10.3, Figs. 1-3: new SEMs of lectotype of Pulvinulina crassata Cushman) (Pl. 10.3, Figs. 5-7: new SEMs of holotype of Globorotalia spinulosa Cushman) (Pl. 10.3, Fig. 16: new SEM of holotype of Pulvinulina crassata var. densa Cushman)
Specimen:
Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 369304
References:

Cushman,J.A. (1925):
An Eocene fauna from the Moctezuma River, Mexico. . Bull. Am. Assoc. Petrol. Geol. Vol. 9 p. 298-303

Cushman,J.A. (1927):
New and interseting foraminifera from Mexico and Texas . Contributions from the Cushman Foundation for Foraminiferal Research Vol. 3 p. 111-119

Cole,W.S. (1927):
A foraminiferal fauna from the Guabal Formation in Mexico . Bulletins of American paleontology Vol. 14 p. 1-46

Howe,H.V. (1939):
Louisiana Cook Mountain Eocene Foraminifera. Louisiana Dep. Cons. . Geol. Surv. Bull. Vol. 14 p. 1-122

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

Cushman,J.A. and Renz,H.H. (1946):
The Foraminiferal Fauna of the Lizard Springs Formation of Trinidad, British West Indies . Cushman Laboratory for Foraminiferal Research, Special Publication Vol. 18 p. 1-48

Subbotina,N.N. (1953):
Iskopaemye foraminifery SSSR (Globigerinidy, Khantkenininidy i Globorotaliidy) . Trudy Vsesoyznogo Nauchno-Issledovatel'skogo Geologo-razvedochnogo Instituta (VNIGRI) Vol. 76 p. 296

Pessagno,J.E.A.. (1961):
The micropaleontology and biostratigraphy of the Middle Eocene Jacaguas Group, Puerto Rico . Micropaleontology Vol. 7 p. 351-358

Bermudez,P.J. (1961):
Contribucion al estudio de las Globigerinidea de la region Caribe-Antillana (Paleocene-Reciente).
In: Boletino Geologia (Venezuela), Special Publicacion Vol. 3

Saito,T. (1962):
Eocene planktonic foraminifera from Hahajima (Hillsborough Island) . Trans. Proc. Paleontol. Soc. Japan, news series Vol. 45 p. 209-225

Aubert,J.. (1963):
Les Globorotalia de la region prerifaine (Maroc septentrional) . Notes et Memoires du Service Geologique Maroc Vol. 22 p. 1-156

Bandy,W.A. (1964):
The type of Globorotalia crassata (Cushman) . Contributions from the Cushman Foundation for Foraminiferal Research Vol. 15 p. 34-35

Postuma,J.A. (1971):
Manual of Planktonic Foraminifera. p. 422 pp

Blow,W.H. (1979):
The Cainozoic Globigerinida. 3 Vols p. 1413 pp

Toumarkine,M. and Luterbacher,H.P. (1985):
Paleocene and Eocene Planktic Foraminifera.
In: Plankton Stratigraphy p. 87-154

Poore,R.Z. and Bybell,L.. (1988):
Eocene to Miocene biostratigraphy of New Jersey Core ACGS # 4: Implications for regional stratigraphy . U. S. Geological Survey Bulletin 1829 p. 1-22

Pearson,P.N.; Olsson,R.K.; Hemleben,C.; Huber,B.T. and Berggren,W.A. (2006):
Atlas of Eocene Planktonic Foraminifera. p. 1-513
Anonymous: Unedited TaxonConcept data
Creative Commons Attribution 2.5 License
This work is licensed under a Creative Commons Attribution 2.5 License.
Back to Search
Taxon relations
pdf
Ranking (experimental)