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Species Morozovelloides coronatus Blow 1979 | ||||||
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| Diagnosis / Definition: | ||||||
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Pearson et al. (2006): DESCRIPTION. Type of wall: Muricate, normal perforate, with concentration of muricae around periphery and on umbilical shoulders of chambers. Test morphology: Low trochospiral, elongateoval to subcircular, moderately lobulate peripheral outline; 5-5 1/2 chambers in relatively evolute coil, subtriangular, weakly inflated, increasing gradually in size; umbilical sutures radial, straight to weakly reflexed at junction with peripheral margin; umbilicus relatively wide, deep and rimmed by distinct circuinumbilical "coronet" of densely clustered/fused muricae on circumumbilical chamber tips; primary aperture a low arch extending nearly to the periphery and rimmed by a thickened margin; about 11 - 12 chambers in 2 1/2-3 whorls (muricate overgrowth on early chambers renders differentiation difficult); chambers vary from lensshaped to trapezoidal (early chambers of last whorl) to subtriangular or subquadrate as a function of disposition of intercameral sutures; flat to slightly concave near peripheral margins; intercameral sutures muricate and limbate, curved, tangential to the periphery in early part of last whorl, radial, straight in terminal part of last whorl, recurved near junction with peripheral, muricocarina; in edge view low, asymmetrically biconvex; umbilicoconvex, early whorl(s) of spiral side slightly elevated; distinct and relatively thick marginal muricocarina Size: Maximum diameter: 0.43 mm (Blow, 1979, p. 1016). |
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| Discussion / Comments: | ||||||
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Pearson et al. (2006): DISTINGUISHING FEATURES.- This taxon is distinguished from the closely related M. crassatus by the distinct circuinumbilical clustering of muricae on the circumumbilical tips of the chambers resulting in the development of a 'coronet' - like ornament. The muricocarina is usually more completely fused than in other species of Morozovelloides. DISCUSSION.- Originally described as coronata, the ending has been changed to agree in gender with the genus Morozovelloides(I CZN, Art. 3 1.2). Blow (1 969, p. 370) differentiated this form based on the circumumbilical muricate 'coronet' and indicated it would be described in a forthcoming paper by himself and one of us (WAB). Tn fact, it was described posthumously by Blow (1979:1016) but not before the name had appeared 5 years earlier in a citation by Fleisher (1974) to what was at the time Blow's manuscript. Article 13(a) of the ICZN Code of Zoological Nomenclature requires every scientific name published after 1930, in order to be available, to be "(1 3.1.1) accompanied by a description or definition that states in words characters that are purported to differentiate the taxon, or (13.1.2) accompanied by a bibliographic reference to such a published statement ..., or (13.1.3) proposed expressly as a new replacement name ...." Fleisher (1974) published an illustration, but included no description of the species; hence (i) is not satisfied (it has to be in words; an illustration is not sufficient), and although he published a citation to Blow, it was to a work not published, and hence (ii) is not satisfied. Fleisher's use of coronata was, therefore, a nornen nudum and hence not available (see above synonymy; information on status of coronatus provided by R. Fleisher, pers. comm., 1998); the species is correctly attributed to Blow (1979). While the gencral morphology of cvassatus and coronatus is similar in many respects and the stratigraphic range is comparable, we retain coronatus for those forms distinguished by the muricate coronet, a wider umbilicus and generally more pronouncedly muricate carina. To investigate the range of variability of coronatus, we have illustrated several new specimens from the type locality in Kilwa, Tanzania (PI. 10.2, Figs. 4-7, 15-16). We note that coronatus displays a greater range in the degree of umbilical vaulting (and hence the peripheral angle as seen in edge view) than crassatus. The typical morphology, as shown by the holotype, is a relatively dorso-ventrally compressed form, but other, more highly vaulted variants occur that are reminiscent of lower Eocene Morozovella,formosa. Some specimens show a transitional morphology to Morozovelloides lehneri (PI. 10.2, Fig. 12). PHYLOGENETIC RELATIONSHIPS.- This species evolved from M. crassatus and was ancestral to M. lehneri. STRATIGRAPHIC RANGE.- Zone E8-E12 (middle Eocene; Blow, 1979). A GEOGRAPHIC DISTRIBUTION.- Apparently characteristic of (sub)tropical Tethyan areas of the world (Caribbean, Indo-Pacific). Citations of its occurrence are too rare to give an accurate picture of its global geographic distribution. STABLE ISOTOPE PALEOBIOL0GY.- Oxygen and carbon isotopes are similar to other Morozovelloides and indicate a shallow water, symbiotic habitat (Wade and others, 2001, Wade and Kroon, 2002; recorded as Morozovella spinulosa). |
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| Systematics: | ||||||
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35 Ordo Foraminiferida Superfamilia Globigerinaceae Familia Truncorotaloididae Genus Morozovelloides Species Morozovelloides coronatus |
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| Synonym list: | ||||||
| Pearson et al. (2006): 1957 Globorotalia spinulosa Cushman. - Bolli : p.168 pl. 38; fig. 6a-7c [middle Eocene Hantkenina aragonensis Zone,
Navet Fm., Trinidad]
p 1957 Globorotalia lehneri Cushman & Jarvis. - Bolli : p.169 pl. 38; fig. 9a-c, 13 [middle Eocene
Porticulasphaera hbckmanni Zone, Navet Fm., Trinidad];
[Not Cushman and Jarvis, 1929]
1962 Globorotalia spinulosa Cushman. - Saito : p.215 pl. 33; fig. 9a-c [middle Eocene, Ha-Ha-Jima, Bonin Islands, Western
Pacific Ocean]; [Not Cushman, 1927]
1969 Globorotalia (Globorotalia) spinulosa Cushman. - Blow : p.370 pl. 50, fig. 2 [Zone P13, Kilwa area, Tanzania]; 4,5 [Zone P11 (not Zone P10 as stated; see
Blow, 1979: 101 7), Kilwa area, Tanzania] [Not Cushman,
1927]
1979 Globorotalia (Morozovella) coronata Blow. - Blow : p.1016 pl. 50, fig. 2-5 (refigured from Blow, 1969, pl. 50);
pl. 168, fig. 1-8 (8=holotype);
pl. 229, fig. 5,6;
pl. 230, fig. 1-6 [Zone P 1 1, Kilwa area, Tanzania]
2004 Morozovella coronata Blow. - Pearson et al. : p.37 pl. 2; fig. 10, 11 [middle Eocene, Zone P 1 1, Tanzania Drilling
Project Site 2, Kilwa Masoka, Tanzania]
2006 Morozovelloides coronatus Blow. - Pearson et al. : p.335 pl. 10.2; fig. 1-16 (Pl. 10.2, Fig. l : holotype of Globorotalia
(Morozovella) coronata Blow, re-illustrated)
(Pl. 10.2, Figs. 2-3: paratypes of Globorotalia
(Morozovella) coronata Blow, re-illustrated)
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| Specimen: | ||||||
| Natural History Museum, London, Inventory number: BP 63/9 |
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| References: | ||||||
Bolli,H.M. (1957): Saito,T. (1962): Blow,W.H. (1969): Blow,W.H. (1979): Pearson,P.N.; Nicholas,C.J..; Singano,J.M..; Bown,P.R..; Coxali,H.K..; van Dongen,B.E..; Huber,B.T.; Karega,A..; Lees,J.A..; Misaky,E..; Pancost,R.D..; Pearson,M.. and Roberts,A.P.. (2004): Pearson,P.N.; Olsson,R.K.; Hemleben,C.; Huber,B.T. and Berggren,W.A. (2006): |
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| Anonymous: Unedited TaxonConcept data | ||||||
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