Taxon Concept provided by
| 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 Subbotina senni Beckmann 1953 | ||||||
|
|
||||||
| Diagnosis / Definition: | ||||||
|
Pearson et al. (2006): DESCRIPTION.- Type of wall: Normal perforate, cancellate, spinose, succulifer-type wall, in adult or terminal stage covered by a thick calcite crust that closes off pores and buries spines. Test morphology: Test trochospiral, moderately elevated initial whorl, globular, ovate to circular in outline, chambers ovoid; in spiral view 4 globular, slightly embracing chambers in ultimate whorl, increasing slowly in size, ultimate chamber may be equal to or smaller in size than penultimate chamber, sutures moderately depressed, straight; in umbilical view 3112 -4 globular, slightly embracing chambers, increasing moderately in size, ultimate chamber may be equal to or smaller in size than penultimate chamber, sutures moderately depressed, straight; umbilicus small, surrounded by heavy build-up of calcite crust, aperture (when visible) umbilical, bordered by thickened rim; in edge view moderately elevated trochospire, chambers ovoid in shape, angled towards the umbilicus, somewhat embracing. Size: Maximum diameter 0.28-0.42 mm. |
||||||
| Discussion / Comments: | ||||||
|
Pearson et al. (2006): DISTINGUISHING FEATURES.- The species is characterized by its globular test, thick calcite crust that covers and closes pores, a moderately elevated trochospire, and the heavy build-up of calcite crust surrounding the umbilicus. DISCUSSION.- The thick calcite crust led Beckmann (1953) to place his new species senni in the genus Sphaeroidinella. Better understanding of the stratigraphic range of planktonic foraminifera, leading to the first detailed zonation of Paleogene and Neogene sections in Trinidad by Bolli (1957) showed that Sphaeroidinella was a Neogene genus. Bolli placed Beckmann's species in Globigerina and showed that it had a lower to middle Eocene range. Subsequently, senni has been placed in Globigerinatheka (Fleisher, 1974), tentatively in Subbotina (Poore and Brabb, 1977), and in Muricoglobigerina (Blow, 1979). Bolli (1972) noted fide Beckmann, 1971) the affinity of the thick wall structure of Globigerina senni with Globigerinatheka subconglobuta micra (Shutskaya), thereby suggesting that the two species were phylogenetically related. Forms identified as G. micra are small, heavily encrusted, and lack identifiable supplementary apertures. Lacking type material, we suggest that these forms are small senni and that micra may be a junior synonym. Globigerina orbformis Cole (a paratype here illustrated in SEM, P1. 6.17, Figs. 5-7) may be a senior synonym but it appears not well enough preserved to make a positive determination and it has rarely been recorded I in the literature. Fleisher (1 974) noted in his study of senni from the middle Eocene at DSDP Site 219, Arabian Sea, that this species may be the direct ancestor of G. micra due to the thickened crust-like wall and compact test, although he did not identify G. micra at Site 219. He placed senni in Globigerinatheka, rather than in Subbotina, due to the closer morphologic affinity ofsenni to this genus, even though the species lacks accessory apertures, a diagnostic feature of Globigerinatheku. Fleisher (1974) described Subbotina kiersteadae from the same section in which he identified senni and regarded it as the ancestral species of G. senni. The holotype of S. kiersteadae (Pl. 6.17, Fig. 16) is a specimen from which the ultimate chamber is broken off. When present it would have covered the umbilical aperture as in senni. The test wall shows the typical encrustation of senni surrounding the umbilicus. It is here regarded as a junior synonym of senni. At Site 2 19 Fleisher recorded S. kiersteadae in Zones E8 and E9, along with G. senni. Blow (1979) erected the genus Muricoglobigerina with Muricoglobigerina soldadoensis soldadoensis (=Acarinina soldadoensis in this work) as the type species. The diagnostic feature of Blow's new genus was the 'murical-sheath', which he described as due to the coalescence of muricae (individual conical projections or pustules from the chamber wall). He emphasized that the murical-sheath was a primary structure and could not be considered as a "calcite crust" (1979, p. 412) or secondary structure caused by latestage calcification. Acarininid taxa with murical-sheaths were placed in Muricoglobigerina, whereas acarininid taxa with individual, separated muricae (pustules) covering the chamber walls were placed in Globorotuliu (Acarinina). Furthermore, Blow regarded Muricoglobigerina soldadoensis as directly ancestral to Muricoglobigerina senni and used specimens identified as senni to illustrate the murical-sheath. However most of the specimens illustrated by Blow as Muricoglobigerina senni are not this species, as it is clear from his images (his pls. 131, 142, 146, 236) that he selected heavily pustulose acarininid specimens in an effort to demonstrate a relationship between these two species. In Acarinina pustules continue to enlarge and coalesce during chamber growth and can form a dense compact structure (the murical-sheath of Blow) in some species. However, the thick wall of senni is due to an additional layer or layers of calcite, thus forming a calcite crust feature in the terminal stage of its life cycle. This can be observed in Plate 6.17, Figs. 9, 10 that show calcification around spines and in Figs. 19,20 where it can be observed that spines were completely buried by late-stage calcification. This feature can be often observed in extant species (Neoglobigerina dutertrei, Sphaeroidinella dehiscens, deep-water Globorotalia etc., Hemleben and others, 1989). This enigmatic species possesses the gross morphology of Subbotina. Globular chambers are arranged in a coil around a small umbilicus, the aperture is umbilically directed, and the aperture is a small arch, although without a distinct lip, bordered by a thin rim. Thickening of the test wall by late-stage gametogenetic calcification is not unusual in Eocene species of Subbotina and extension of the ultimate chamber over the umbilicus is also seen in the species S. angiporoides, S. jacksonensis, and S. utilisindex. PHYLOGENETIC RELATIONSHIPS.- The origin of Subbotina senni is uncertain but we suggest that S. roesnaesensis is the most likely ancestor. Subbotina senni has been suggested by ~ o l l(i1 972) as an ancestor to the genus Globigerinatheka. Blow (1979) thought that it might be an ancestor to Globigerinatheka index. Following observations of wall texture and dissected specimens of senni, Guembelitroides nuttalli and globigerinathekides, we conclude that the most likely ancestor of Globigerinatheka is G. nuttalli (see Chapter 7). GEOGRAPHIC DISTRIBUTION.- Global in low to mid latitudes. STABLE ISOTOPE PALEOBIOL0GY.- Subbotina senni apparently occupied a mixed layer habitat (Pearson and others, 1993,2001). It records more negative ò18O values than do species of Catapsydrax, Hantkenina, and other species of Subbotina. It is less enriched in ò13C values than species of Acarinina and Morozovella. Subbotina senni may have been a shallow mixed layer species that sank to middle mixed layer or deeper depths during gametogenesis. The isotope values may display a shallow life style during the juvenile through preadult stage and adding a calcite crust below the thermocline (Pearson and others, 1993). |
||||||
| Systematics: | ||||||
|
35 Ordo Foraminiferida Superfamilia Globigerinaceae Familia Globigerinidae Genus Subbotina Species Subbotina yeguaensis |
||||||
| Synonym list: | ||||||
| Pearson et al. (2006): ? 1927 Globigerina orbiformis Cole. - Cole : p.33 pl. 5; fig. 7 [middle
Eocene, Guayabal Fm., Tampico, Mexico]
1953 Sphaeroidinella senni Beckmann. - Beckmann : p.394 pl. 26; fig. 2-4; text-fig. 20 [middle Eocene, Mount Hillaby, Barbados]
1957 Globigerina senni Beckmann. - Bolli : p.163 pl. 35; fig. 10a-12 [middle Eocene Porticulasphaera mexicana Zone,
Navet Fm., Trinidad]
? 1958 Globigerinoides subconglobatus var. micra Shutskaya. - Shutskaya : p. 87-88 pl. 1; fig. 1 (holotype), 2, 3 [middle Eocene, associated with Globorotalia
aragonensis, Cherkesskiy horizon, Nagutskoye Well, N.
Caucasus]
1974 Globigerinatheka senni Beckmann. - Fleisher : p.1021 pl. 8; fig. 10, 11 [middle Eocene Zone E9, DSDP Site
2 19, Laccadive Ridge, eastern Arabian Sea]
? 1974 Subbotina kiersteadae Fleisher. - Fleisher : p.1032 pl. 16; fig. 1-9 [middle Eocene Zone E9, DSDP Site 219, Laccadive
Ridge, eastern Arabian Sea]
1975 Globigerina senni Beckmann. - Toumarkine : p.750 pl. 5; fig. 5-11 [figs. 5-8, middle Eocene, DSDP Site 305, Shatsky
Rise, northwest Pacific Ocean; figs. 9-1 1, middle Eocene,
DSDP Site 313, northeastern Mid-Pacific Mountains,
Central Pacific Ocean]
1976 Globigerina (Eoglobigerina) senni Beckmann. - Hillebrandt : p.335 pl. 3; fig. 10-13 [lower Eocene
Globorotalia palmerae Zone, southeastern Spain]
1977 "Subbotina" senni Beckmann. - Poore & Brabb : p.269 pl. 3; fig. 12-14 [middle Eocene, Twobar Shale,
San Lorenzo Fm., Santa Cruz Mountains, California]
1978 Globigerina senni Beckmann. - Toumarkine : p.718 pl. 10; fig. 10-14 [middle Eocene, Angola Basin, DSDP Site 364,
southeastern South Atlantic Ocean]
p 1979 Muricoglobigerina senni Beckmann. - Blow : p.1131 pl. 165; fig. 8 (partim; not pl. 131: Figs. 7-9; pl. 142: figs. 7,9; pl. 146:
figs. 9, 10; pl. 236: Figs. 1-4.); [middle Eocene Zone E8, Kane 9, core 42, Endeavour
Seamount, equatorial Atlantic Ocean]
1983 Globigerinatheka senni Beckmann. - Pujol : p.651 pl. 6; fig. 3 [lower Eocene Zone E7, DSDP Hole
5 15B, Brazil Basin, South Atlantic Ocean]
1985 Globigerina senni Beckmann. - Toumarkine & Luterbacher : p.127 fig. 28, 1-5 (fig. 28, la-c,
reillustration of holotype, pl. 26: fig. 2a-c);
fig. 28, 2, 3 [middle Eocene Orbulinoides beckmanni Zone, Navet Fm., Trinidad];
fig. 28, 4, 5 (reillustration of Toumarkine, 1975,
pl. 5: figs. 9, 10)
non 1988 Muricoglobigerina senni Beckmann. - Huber : p.440 pl. 7; fig. 21
2001 Muricoglobigerina senni Beckmann. - Warraich & Ogasawara : p.42 fig. 11: 6-8 [Zone E1011 1, Kirthar
Fm., Snlaiman Range, Pakistan]
2004 Subbotina senni Beckmann. - Pearson et al. : [lower Eocene Zone P819, Tanzania]
2006 Subbotina senni Beckmann. - Pearson et al. : p.151 pl. 17; fig. 1-20 (Pl. 6.17, Figs. 1-3: new SEMs of holotype of
Sphaeroidinella senni Beckmann)
(Pl. 6.17, Figs. 5-7: new SEMs of holotype of
Globigerina orbiformis Cole)
|
||||||
| References: | ||||||
Cole,W.S. (1927): Beckmann,J.P. (1953): Bolli,H.M. (1957): Shutskaya,E.K. (1958): Fleisher,R.L. (1974): Toumarkine,M. (1975): Hillebrandt,A. (1976): Poore,R.Z. and Brabb,E.E.. (1977): Toumarkine,M. (1978): Blow,W.H. (1979): Pujol,C. (1983): Toumarkine,M. and Luterbacher,H.P. (1985): Huber,B.T. (1988): Warraich,M.Y.. and Ogasawara,K.. (2001): 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): |
||||||
| Anonymous: Unedited TaxonConcept data | ||||||
 This work is licensed under a Creative Commons Attribution 2.5 License. | ||||||
| Back to Search | ||||||
|
Taxon relations
Ranking (experimental) |
||||||