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Anonymous: Unedited TaxonConcept data | ||||||
Notice: This catalogue page may contain unedited data.
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Species Globigerinatheka semiinvoluta Keijzer 1945 | ||||||
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Alternative name: | ||||||
Diagnosis / Definition: | ||||||
Pearson et al. (2006): DESCRIPTION. Tvpe of wall: Spinose, cancellate, thin, with a high density of pores, < 0.04 mm in diameter. Test morphology: Test spherical with a very large hemispherical last chamber embracing half or more of the earlier chambers with one to four prominent, circular, secondary apertures (commonly 3) mainly bordered by a marked rim; early chambers coiled in a low and rather short trochospire, separated by poorly visible sutures that become slightly more distinct and slightly depressed in the adult. Size: The size of specimens is highly variable. Diameter may be up to 0.55 mm, however much smaller specimens are common especially in mid latitudes. In smaller morphotypes, the hemispherical last chamber shows much smaller or even poorly visible secondary apertures. |
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Discussion / Comments: | ||||||
Toumarkine & Luterbacher (1985): The main character of G. semiinvoluta is the final hemispherical chamber which embraces nearly half of the earlier test and the high-arched to circular sutural apertures with distinct rims. However, a great amount of intraspecific variability can be seen in the dimensions of the test as well as the size and the number and shape of the apertures. This variability is due to ecologic conditions: the typical specimens found in tropical areas (Figs. 39.8, 15, 17) are generally larger with better developed apertures than those of the temperate areas (Figs. 39.1-6, 12-14). The number of apertures (1 to 4, commonly 2 or 3) is not directly related to the size of the specimen. G. semiinvoluta differs from G. index tropicalis by its larger and more embracing final chamber and its less incised sutures. It differs from G. mexicana mexicana by the same characters and also by its generally larger size, at least in tropical regions. Pearson et al. (2006): DISTINGUISHING FEATURES.- Globigerinatheka semiinvoluta differs from all the other globular globigerinathekids by its very inflated enveloping last chamber, its large and noticeably rimmed, circular secondary apertures, much shorter initial trochospire and mainly indistinct sutures. Globigerinatheka mexicana and G. semiinvoluta differ by the circular apertures with distinctive rims in G. semiinvoluta, which are not present in G. mexicana. G. semiinvoluta is distinguished from G. tropicalis by an embracing final chamber. DISCUSSION.- Originally described as Globigerinoides semi-involutus by Keijzer, the hyphen has been removed (ICZN, Art. 32.5) and the ending has been changed to agree in gender with Globigerinatheka (ICZN, Art. 31.2). Bolli (1957) designated hypotypes of G. semiinvoluta from the type locality (Navet Formation, Trinidad). Blow and Saito (1 968a) suggested that G. semiinvoluta was synonymous with G. mexicana. However, we recognise G. semiinvoluta and G. mexicana as taxonomically and stratigraphically distinct, although transitional forms occur in uppermost Zone E13 to lowermost Zone E14. Blow (1979, p. 788) stated that G. korotkovi is taxonomically indistinguishable from G. semiinvoluta even though the former species is high spired; he also included G. lindiensis (here considered a synonym of G. tropicalis) saying it is not worth differentiating this species taxonomically from G. semiinvoluta (p. 791) as well as G. rubriformis (here G. korotkovi) that he considered as immature specimens of G. semiinvoluta (p. 8 13). Blow (1 979) included G. semiinvoluta in the genus Porticulasphaera, emended, here considered a junior synonym of Globigerinatheka. Toumarkine (1975) attributed to G. semiinvoluta (and illustrated) two small specimens from Shatsky Rise that exhibit a very rough surface. PHYLOGENETIC RELATIONSHIPS.- Blow and Banner (1962) suggested that G. semiinvoluta evolved from G. tropicalis, a relationship that is not supported here. In the western North Atlantic (ODP Site 1052), G. semiinvoluta appears to descend from G. mexicana, a phylogeny also proposed by Bolli (1972) and Blow (1979). The distinct rimmed apertures and less depressed sutures developed in the upper middle Eocene to lower upper Eocene with trandtional forms evident in uppermost E1 3 to lowermost E1 4. GEOGRAPHIC DISTRIBUTION.- Globigerinatheka semiinvoluta is common in low latitudes, with well developed large specimens, and extends to temperate latitudes with smaller specimens. It is absent in high latitudes. STABLE ISOTOPE PALEOBIOL0GY.- Oxygen and carbon isotopic data indicate that G. semiinvoluta occupied a mixed layer habitat (Poore and Matthews, 1984; Pearson and others, 2001; Wade and Kroon, 2002, referred to as G. mexicana). |
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Systematics: | ||||||
15 Classis Foraminifera Genus Globigerinatheka Species Globigerinatheka semiinvoluta 35 Ordo Foraminiferida Superfamilia Globigerinaceae Familia Globigerinidae Genus Globigerinatheka Species Globigerinatheka semiinvoluta |
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Synonym list: | ||||||
Toumarkine & Luterbacher (1985): 1945 Globigerinoides semiinvolutus Keijzer. - Keijzer : p.206 pl 4 figs 58a-e (type reference)
1985 Globigerinatheka semiinvoluta Keijzer. - Toumarkine & Luterbacher : 141, 145 figs 37.11, 39.1-17
Pearson et al. (2006): 1945 Globigerinoides semiinvolutus Keijzer. - Keijzer : p.206 pl. 4; fig. 58a-e (holotype) [upper Eocene, San Luis Fm.,
Guantanamo Basin, Cuba]
1953 Globigerinoides index Finlay. - Beckmann : pl. 25; fig. 14 [upper Eocene, Oceanic Fm., Barbados]; [Not Finlay,
1939]
1957 Globigerapsis semiinvoluta Keijzer. - Bolli et al. : p.34 pl. 6; fig. 7a-c [upper Eocene, Navet
Fm., Trinidad]
1957 Globigerapsis semiinvoluta Keijzer. - Bolli : p.165 pl. 36; fig. 19-20 (hypotypes) [upper Eocene Globigerapsis semiinvoluta
Zone, Navet Fm., Trinidad]
1962 Globigerapsis semiinvoluta Keijzer. - Blow & Banner : p.125 pl. 15; fig. J-K, ?L [upper Eocene
Globigerapsis semi-involuta Zone, Lindi area, Tanzania]
non 1963 Globigerapsis semiinvoluta Keijzer. - Eckert : p.1063 pl. 7; fig. 1a-3c [upper Eocene, Schimberg
Section, Swiss Alps]; (= G. luterbacheri)
1968 Globigerapsis semiinvoluta Keijzer. - Samuel & Salaj : pl. 21; fig. 3a-c [upper Eocene Globigerapsis index
Zone, Kravany, Carpathians, Slovakia]
1969 Globigerapsis mexicana Cushman. - Blow : p.330 pl. 27; fig. 3-4 [upper Eocene Zone P15, Lindi area,
Tanzania]
1971 Globigerapsis mexicana Cushman. - Postuma : fig. at p. 141 [Trinidad]
1971 Globigerapsis mexicana Cushman. - Raju : pl. 11; fig. 1-6 [upper Eocene, Cauvery basin,
S. India]; [Not Cushman, 1925]
non 1971 Globigerinatheka (Globigerapsis) semiinvoluta Kejizer. - Jenkins : p.188 pl. 21; fig. 633-634 [upper
Eocene, upper type Runangan, Port Elisabeth Section,
New Zealand]; (= G. tropicalis)
1972 Globigerinatheka semiinvoluta Keijzer. - Bolli : p.131 pl. 5, fig. 1-27;
pl. 6, fig. 1-17 [upper Eocene Globigerinatheka semiinvoluta Zone type locality, Navet Fm., Trinidad];
text-fig. 72-76 (redrawn holotype);
text-fig. 77-78 (from Bolli and others, 1957); text-fig. 79 (from Blow and Banner, 1962)
1975 Globigerinatheka semiinvoluta Keijzer. - Stainforth et al. : p. 223-225 fig. 83.1-2, 6 [upper Eocene, Navet Fm., Trinidad];
fig. 83.3-4 (from Bolli, 1972);
fig. 83.5, 7 (refigured from Blow and Banner, 1962)
1975 Globigerinatheka semiinvoluta Keijzer. - Toumarkine : pl. 4, ?fig. 17, 18 [upper Eocene Globigerinatheka
semiinvoluta Zone, DSDP Site 305, Shatsky Rise, northwest
Pacific Ocean]
1975 Globigerinatheka semiinvoluta Keijzer. - Toumarkine & Bolli : pl. 6; fig. 15-24 [upper Eocene Globigerinatheka
semiinvoluta Zone, Possagno Section, northern Italy]
1978 Globigerinatheka semiinvoluta Keijzer. - Toumarkine : pl. 5, fig. 1-14 [upper Eocene Globigerinatheka semiinvoluta Zone, DSDP Site 363, South Atlantic Ocean];
pl. 5, figs. 15-21 [upper Eocene Globorotalia cerroazulensis s.l. to Globigerinatheka
semiinvoluta Zone, DSDP Site 360, South Atlantic
Ocean]
1979 Porticulasphaera semiinvoluta Keijzer. - Blow : pl. 27, fig. 3-4 (new name for Globigerapsis mexicana of Blow, 1969);
pl. 240, figs. 9-10 [upper Eocene Zone P15, Lindi area, Tanzania]
1980 Globigerinatheka semiinvoluta Keijzer. - Salaj : pl. 27; fig. 11 [middle Eocene
?Zone P1 5, Bartonian, Dj. Fkirine, Tunisia]
1983 Globigerinatheka semiinvoluta Keijzer. - Toumarkine : pl. 20, fig. 1 [upper Eocene, Menton, Southern France];
fig. 2 [upper Eocene G. semiinvoluta Zone, Contes Section, Southern France];
fig. 3-4 [upper Eocene G. semiinvoluta Zone, Possagno Section, northern Italy];
fig. 7 [upper Eocene G. semiinvoluta Zone, DSDP
Site 522, South Atlantic Ocean];
fig. 8-11 (from Bolli, 1972);
fig. 12- 14 [upper Eocene G. semiinvoluta Zone,
DSDP Site 363, South Atlantic Ocean]
? 1983 Globigerinatheka semiinvoluta Keijzer. - Pujol : pl. 8; fig. 7, ?8 [upper Eocene Zone P 15-1 6, DSDP Hole
5 16F, Rio Grande Rise, South Atlantic Ocean]
1986 Porticulasphaera semiinvoluta Keijzer. - Molina et al. : pl. 1; fig. 6a-b [upper Eocene Porticulasphaera semiinvoluta
Zone, Fuente Caldera Section, south-east Spain]
1988 Globigerinatheka semiinvoluta Keijzer. - Coccioni et al. : pl. 1; fig. 10 [upper Eocene Zone P15,
Massignano Section, Marche, Italy]
1991 Globigerinatheka semiinvoluta Keijzer. - Nocchi et al. : pl. VI; fig. 11 [upper Eocene Zone P15,
Umbria, central Italy]
non 1991 Globigerinatheka cf. semiinvoluta Keijzer. - Miller et al. : p.35 Appendix 1; fig. 1-8 [upper Eocene Zone
P15, DSDP Site 612, western North Atlantic]; (= G.
tropicalis)
1994 Globigerinatheka cf. semiinvoluta Keijzer. - Nishi & Chaproniere : pl. 2; fig. 19-21 [upper Eocene Zones
P1 5-P1 6, ODP Hole 841B, south-west Pacific Ocean]
1995 Globigerinatheka semiinvoluta Keijzer. - Poag & Commeau : pl. 5; fig. 14 [upper Eocene Zone P15, Exmore core, Salisbury
Embayment, Virginia-Maryland]
2006 Globigerinatheka semiinvoluta Keijzer. - Pearson et al. : p.199 pl. 7.9; fig. 1-15
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Was used in synonym list of: | ||||||
Specimen: | ||||||
Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 5726a Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 5726b |
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References: | ||||||
Keijzer,F.G. (1945): Beckmann,J.P. (1953): Bolli,H.M.; Loeblich,A.R. and Tappan,H. (1957): Bolli,H.M. (1957): Blow,W.H. and Banner,F.T. (1962): Eckert,H.R.. (1963): Samuel,O.. and Salaj,J. (1968): Blow,W.H. (1969): Raju,D.S.N. (1971): Jenkins,D.G. (1971): Postuma,J.A. (1971): Bolli,H.M. (1972): Toumarkine,M. (1975): Toumarkine,M. and Bolli,H.M. (1975): Stainforth,R.M.; Lamb,J.L.; Luterbacher,H.P.; Beard,J.H. and Jeffords,R.M. (1975): Toumarkine,M. (1978): Blow,W.H. (1979): Salaj,J. (1980): Toumarkine,M. (1983): Pujol,C. (1983): Toumarkine,M. and Luterbacher,H.P. (1985): Molina,E..; Monaco,P..; Nocchi,M. and Parisi,G.. (1986): Coccioni,R.; Monaco,P..; Monechi,S..; Nocchi,M. and Parisi,G.. (1988): Nocchi,M.; Amici,E. and Premoli Silva,I. (1991): Miller,K.G.; Berggren,W.A.; Zhang,J.. and Palmer-Julson,A.A.. (1991): Nishi,H.. and Chaproniere,G.C.H. (1994): Poag,C.W.. and Commeau,J.A.. (1995): 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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