Globigerinatheka


Classification: pf_cenozoic -> spinose -> Globigerinidae -> Globigerinatheka
Sister taxa: Catapsydrax, Eoglobigerina, Globigerina, Globigerinatheka, Globorotaloides, Globoturborotalita, Guembelitrioides, Orbulinoides, Paragloborotalia, Parasubbotina, Pseudoglobigerinella, Subbotina, Turborotalita,
Daughter taxa (blue => in age window 0-300Ma)
Globigerinatheka barri is characterized by its numerous secondary apertures with bullae. It differs from G. mexicana in having fewer chambers in the first whorl which are arranged in a slightly higher trochospire, more depressed sutures throughout the test, and a smaller flatter last chamber which occupies a maximum of one third of the entire test (instead of half of it, as in G. mexicana). Even
though several features, like the secondary apertures, are masked by numerous bullae, G. barri differs from G. kugleri in having the test nearly globular instead of roughly subtriangular, a less lobate and more compact outline, subcircular apertures instead of rather wide low arches, and common bullae with subcircular accessory apertures.
Globigerinatheka curryi is loosely coiled with deeply incised sutures and inflated chambers. It differs from G. kugleri by its longer initial spire with more numerous chambers and larger size; it differs from G. euganea by its shorter inner spire with fewer chambers, less numerous secondary apertures, less globular general shape, more moderate size of the last chambers and more distinct and depressed sutures especially in the outer whorl. Globigerinatheka curryi is morphologically close to G. luterbacheri from which it differs in having a lower spire resulting in a shape that is more subglobular.
Globigerinatheka euganea has a compact, spherical test, with small, numerous secondary apertures in some specimens. It differs from G. curryi by having a more compact test, a tighter inner coil and more numerous and smaller secondary apertures. It differs from G. luterbacheri by having a more spherical test and less depressed sutures; it differs from beckmanni by less numerous, slightly larger secondary apertures, rarely recorded along the inner spire, and by the absence of areal openings.
Globigerinatheka index is distinguished by its well defined incised sutures and large, high-arched, primary aperture located above the suture between the first two chambers of the final whorl. This taxon differs from G. tropicalis by its semicircular, rimmed apertures and deeply incised distinct sutures.
Test subtriangular in outline, rather lobate, with three chambers in the outer whorl rapidly increasing in size as added, sutures depressed in the outer whorl; low arched primary and secondary sutural apertures that may be covered by slightly inflated bullae. G. kugleri differs from G. mexicana by the subtriangular outline, its distinct sutures and low arched apertures.
The more ovoid, somewhat more irregular test and the rather incised sutures distinguish G. luterbacheri from the other large globigerinathekids. Globigerinatheka luterbacheri differs from G. kugleri in its more robust wall and more compact test of larger size, more incised sutures and more numerous secondary apertures and from G. mexicana and G. barri in the more robust wall, the longer spire, more numerous secondary apertures, more incised sutures, and distinctly larger size.

Globigerinatheka mexicana is characterized by its nearly spherical test and large inflated last chamber that comprises about half of the entire test. It differs from G. semiinvoluta by its less embracing last chamber and smaller secondary apertures that lack a rim, from G. barri by its larger hemispherical last chamber, less depressed sutures throughout, spherical outline and less common bullae, and from G. kugleri by its more spherical test and less distinct sutures.
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.
Globigerinatheka subconglobata is characterized by its evolute outline, four chambers in the last whorl, crown-like flatter final chamber, small apertures and initial spire which is central in position. Globigerinatheka subconglobata shows some variability in the size and shape of the primary and secondary apertures, whereas the general size of the test is highly variable (see above). In smaller morphotypes, secondary apertures are small or even poorly visible. The wall of G. subconglobata is frequently recrystallized.
The distinctly depressed sutures, medium low spire and mainly subcircular apertures with rims characterize G. tropicalis. Globigerinatheka tropicalis has frequently been confused with G. index. According to Blow and Banner (1962), G. tropicalis differs from G. index in lacking the very thick wall, deeply incised sutures, and heavily granular surface characteristic of G. index. In addition, G. tropicalis exhibits a less compact outline, smaller and less subcircular primary aperture without a thick lip, and more numerous smaller secondary apertures than G. index. Bolli (1972) agreed with Blow and Banner (1962) in including some of his specimens identified as G. index in G. tropicalis. Meanwhile, it is hard to separate Globigerinatheka lindiensis from G. tropicalis, except for the presence of bullae in the former, and in agreement with Bolli (1972), we consider G. lindiensis a junior synonym of G. tropicalis. Blow (1979) considered G. tropicalis as junior synonym of G. mexicana mexicana (p. 825), but in our opinion, these two taxa are not conspecific. Globigerinatheka tropicalis differs from G. semiinvoluta by its less compact test, less embracing final chamber, distinct sutures and mainly high arched apertures.
This morphotype is characterized by a high trochospire with three chambers in the last whorl, a rather compact peripheral outline and subcircular primary and supplementary apertures. Based on the presence of at least one supplementary aperture, the species korotkovi is included here in the genus Globigerinatheka. Globigerinatheka korotkovi differs from Subbotina’s species rubriformis in having a much shorter (not turreted) spire and at least one subcircular supplementary aperture; it differs from G. subconglobata in having a last chamber that is much larger, and subcircular openings much smaller than G. index.
Specimens which cannot be assigned to established species

Taxonomy

Citation: Globigerinatheka Bronnimann, 1952, emended Proto Decima and Bolli, 1970
Rank: Genus
Type species: Globigerinatheka barri Bronnimann, 1952
Synonyms:
Taxonomic discussion: The globigerinathekids display an enormous amount of morphological variability in features such as test size and the number, shape and size of secondary apertures. The complexities surrounding the genus Globigerinatheka are best summarized chronologically.
1952 - Bronnimann (1952) erected the genus Globigerinatheka comprising only the new species G. barri, the type species. He characterized the genus as having an almost spherical trochospiral test with four chambers in last whorl and “composite supplementary chambers, consisting of a single large inflated primary chamber across the umbilicus and of three small, only slightly inflated secondary chambers” (structures that are recognized here as bullae), with multiple (maximum of nine), small semicircular apertures in secondary chambers.
1957 - Bolli and others (1957) erected the genus Globigerapsis, with the new species G. kugleri as the type species, to accommodate subspherical forms similar to the genus Globigerinatheka but devoid of bullae covering the secondary apertures. These authors included in the new genus the species Globigerinoides semiinvoluta Keijzer and a specimen identified by Bermudez (1949) as Globigerina mexicana Cushman that, according to them, may be closer to semiinvoluta. In the same paper Bolli and others (1957) also erected the genus Porticulasphaera, with Globigerina mexicana Cushman as the type species, which differed from Globigerapsis “in having the Globigerinoides-type of secondary apertures on the spiral side in the early coil.”
1962 - Saito (1962) observed that the description of Porticulasphaera mexicana by Bolli, Loeblich and
Tappan (1957) did not correspond to the characters of the mexicana holotype, and re-named the Bolli, Loeblich and Tappan species Porticulasphaera beckmanni; in addition he included the true mexicana in the genus Globigerapsis.
1968 - Blow and Saito (1968a) re-examined and re-illustrated the holotype of G. mexicana and reiterated that Cushman’s species belonged to the genus Globigerapsis. They stated also that the species mexicana is similar and conspecific with Globigerapsis semiinvoluta (Keijzer), which they consequently considered a junior synonym of G. mexicana, a synonymy rejected here and also by Bolli (1972). These authors also erected the new genus Orbulinoides for Saito’s species beckmanni, invalidating the genus Porticulasphaera due to a misidentification of type species. However, the new combination Orbulinoides beckmanni was published a few months earlier by Cordey (1968), who became the author of the genus Orbulinoides (see the discussion below under Orbulinoides).
1970 - Proto Decima and Bolli (1970) observed that all the species included in the genus Globigerapsis may possess bullae. Consequently, this made the genus Globigerapsis a junior synonym of Globigerinatheka. These authors also revised and emended the genus Orbulinoides, which is characterized by possessing numerous sutural supplementary apertures that in the early stage open into vestibules, the thick wall of which has separate apertures. It also has few areal apertures in the last, large enveloping chamber, and some irregular bulla-like structures (see below).
1972 - Bolli (1972) revised the genus Globigerinatheka in which he distinguished four morphologically distinct species, containing 12 subspecies, as follows:
1) Group ‘mexicana’, characterized by small size, a more or less globular test and frequent bullae, that includes mexicana mexicana, mexicana barri, mexicana kugleri.
2) Group ‘subconglobata’, characterized by a large (except micra) globular test size, robust walls and occasional bullae, that includes subconglobata subconglobata, subconglobata micra, subconglobata curryi, subconglobata euganea, subconglobata luterbacheri. According to Bolli (1972), the subspecies curryi is the first member of the lineage leading to “beckmanni” via euganea, in the process changing the test outline from subtriangular in curryi to almost circular in euganea, initially with 3 chambers in the last whorl. Further changes include an increase in the length of the somewhat flat initial spire and increases in the size of the last chamber and in the degree of chamber envelopment.
3) Group ‘index’, characterized by an elongate test shape and apertures that are usually not covered by bullae, that includes index index, index korotkovi, index tropicalis and index rubriformis.
4) G. semiinvoluta, characterized by an almost spherical test with short flat inner spire and a well-developed hemispherical last chamber with more or less large circular openings.
1979 - Blow (1979) re-emended the three genera Globigerinatheka, Porticulasphaera and Globigerapsis and attributed the species previously mentioned as follows:
1) Globigerinatheka, monotypic, including only the type species barri, characterized “by consistently possessing true bullae covering the supplementary apertures of the last chamber”, “in having a long earlier trochospiral stage in ontogeny” with streptospiral coiling mode affecting only the last two chambers, and a wall “of normal globigerinacean type”, bearing “normal long, acicular, spines” without murical sheath.
2) Porticulasphaera, characterized by a rather short trochospiral stage, a large last chamber that “may embrace a considerable part of the earlier test”, a normal globigerinacean type, non-muricate wall and apparently without bullae. It includes two subgroups:
A – mexicana, including mexicana mexicana, senior synonym of tropicalis, here considered as a discrete taxon, and mexicana howei, here considered to belong to the genus Catapsydrax,
B – semiinvoluta, senior synonym of lindiensis (here lindiensis is considered a junior synonym of G. tropicalis).
3) Globigerapsis, characterized by a wall bearing closely packed muricae forming a murical sheath, that may appear as a thickened wall; a streptospiral coiling mode early in ontogeny; multiple sutural secondary apertures in chambers prior to the last one, small areal apertures in some forms and possible presence of small bullae. It includes three subgroups:
A – beckmanni,
B – index, the intermediate member of the plexus Muricoglobigerina senni -index -kugleri,
C – kugleri, including kugleri kugleri, kugleri curryi, and kugleri euganea.
Blow (1979) also stated that if bullae were not to be considered as having taxonomic importance as well as secondary apertures in earlier chambers, then the species he included in Porticulasphaera “should be transferred to the genus Globigerinatheka”. Conversely, Blow (1979) said that Globigerinatheka has distinctly different ancestry from the genus Globigerapsis and the “gross homeomorphy” of taxa belonging to both genera is “due to phyletic convergent evolution” and transitional forms are lacking. Wall texture studies by our Working Group (Hemleben and Olsson, this volume) have failed to find evidence of Blow’s “murical sheath” structure, and all of the species included by him in Globigerapsis are certainly spinose, hence we do not regard any of the groups as likely descendants of the Acarinina group (which includes Blow’s genus Muricoglobigerina) (see Hemleben and Olsson, Chapter 4, this volume).
Concerning the genus Orbulinoides, Blow (1979), in agreement with Proto Decima and Bolli (1970) and Bolli (1972), considered the species beckmanni as the end member of the curryi -euganea lineage, but he assigned it to the genus Globigerapsis with its ancestral forms, saying that it is not necessary to include “beckmanni” in a different genus.
1983 and 1985 - Toumarkine (1983) and Toumarkine and Luterbacher (1985) rejected the generic classification of Blow (1979). They retained the genus Globigerinatheka, comprising the groups/lineages identified by Proto Decima and Bolli (1970) and Bolli (1972), and the genus Orbulinoides for the species beckmanni.
To summarize, in disagreement with Blow’s (1979) observations, our study demonstrates that none of the species included by him in the genus Globigerapsis possess a muricate wall, but they do have the same wall texture as Globigerinatheka. Thus, lacking any criteria for distinguishing the three genera, the only genus retained here is Globigerinatheka, and both Porticulasphaera and Globigerapsis must be considered junior synonyms of the former. On the other hand, the presence of numerous, closely spaced, sutural secondary apertures as well as few areal apertures (never observed in any of the globigerinathekids; see also Proto Decima and Bolli, 1970), appears to be a valid criterion for keeping Orbulinoides as a separate genus, analagous to the manner in which the Miocene Praeorbulina- Orbulina plexus is distinguished from the genus Globigerinoides.
Finally, we discuss Globigerina orbiformis Cole, 1927. Under this name Cole (1927) described, and poorly illustrated, a spherical form with small supplementary apertures and smaller than mexicana (about half the size), with a rougher surface, that he regarded as the ancestor of Cushman’s G. mexicana. From our SEM photographs of the type series, the four paratypes all share a strongly cancellate wall, with most diagnostic features masked by strong recrystallization. The general shape varies from subglobular to sac-like, in the latter case possibly related to a long, rather high spire. There are 3 to 4 chambers in the last whorl; sutures are not visible in most of the test except between the last two chambers where they are slightly depressed; the primary aperture is umbilical in position, with a low wide arch and rough border; secondary apertures were not positively detected in any specimens. This rarely recorded species (a poor drawing was given by Bermu½dez, 1949, and short comments by Hagn, 1956) appears to be closer to Subbotina senni than to globigerinathekids, as previously suggested by Beckmann (in Bolli, 1972, p. 134).
PHYLOGENETIC RELA TIONSHIPS.— As observed by Proto Decima and Bolli (1970) and Bolli (1972), the globigerinathekids display morphological similarities or differences at the species level concerning the length and growth rate of the inner spire, and the size and enveloping degree of the last chamber. These allow us to suggest possible phylogenetic relationships and are reported in the description of each species and graphically plotted in Figure 7.1.
The first globigerinathekid to evolve was Globigerinatheka subconglobata, which has been positively indentified in the middle part of the lower
middle Eocene, Zone E8. The appearance of true globigerinathekids was preceded by the presence of morphotypes without secondary apertures and/or bullae that suggest a relationship with Guembelitriodes nuttalli, with which they share a similar cancellate, spinose wall texture (see the introduction to this chapter and Plate 7.1). G. subconglobata apparently gave rise over a very short time span to several other globigerinathekids in Biochron E9.
The first species to evolve after G. subconglobata was the subtriangular shaped G. kugleri which, in agreement with Blow (1979), is considered to be the ancestral member of the G. curryi -Orbulinoides beckmanni lineage, which evolved via G. euganea (see Bolli, 1972), the transition being characterized by the progressive increase in the enveloping degree of the last chamber, accompanied by the increase in length of the inner spire, eventually producing the spherical shape of Orbulinoides beckmanni; G. luterbacheri appears to branch off independently from G. euganea in E12.
At the same time, a second morphologic transition occurred, also characterized by the increase in streptospirality and of the degree of embrace of the final chamber, leading to a subspherical outline. In this way, G. mexicana branched off from G. subconglobata. The former developed a much larger last chamber, which strongly embraces the previous whorls, and probably gave rise to its end member G. semiinvoluta in the latest middle Eocene. Even though several authors considered G. barri as closely related to G. mexicana, it is more likely that G. barri descended independently from G. subconglobata.
Within E9, a third evolutionary trend in Globigerinatheka occurred, in which the 4-chambered subglobular outline of G. subconglobata evolved to be more rectangular with basically three chambers in the last whorl. This gave rise to the high-spired G. korotkovi, and independently to the subrectangular G. index with incised sutures in late E9. We consider G. index to be ancestral to G. tropicalis, which appears in mid Zone E13.
[Eocene Atlas]

Catalog entries: Globigerinatheka;

Type images:

Short diagnosis: Globigerinathekids are characterized by medium to large-sized subspherical to spherical tests and multiple secondary apertures that are frequently covered by bullae.

NB The short diagnoses are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus. They have initially been copied from the diagnostic characters/distinguishing features sections of the Eocene and Paleocene Atlases, they will be edited as the site is developed.

Description


Diagnostic characters: Globigerinathekids are characterized by medium to large-sized subspherical to spherical tests and multiple secondary apertures that are frequently covered by bullae.
[Premoli Silva et al. 2006]

Wall type: Spinose, cancellate; commonly covered by a thick calcite crust. [Premoli Silva et al. 2006]

Test morphology: Test moderately low trochospiral, globular, lobulate in outline, chambers globular; in spiral view 4-5 globular, slightly embracing chambers in ultimate whorl, increasing moderately in size, sutures depressed, straight; in umbilical view 4-5 globular, slightly embracing chambers, increasing moderately in size, sutures depressed, straight, umbilicus small, open, enclosed by surrounding chambers, aperture umbilical, a rounded arch, bordered by a thickened rim or thin lip; in edge view chambers globular in shape, slightly embracing, umbilical aperture may be partly visible.
Size: Maximum diameter generally less than 0.20 mm.
[Premoli Silva et al. 2006]

Biogeography and Palaeobiology

Biostratigraphic distribution

Geological Range:
Notes: Globigerinathekids range from the lower middle Eocene Zone E8 (=P10) to around the Eocene/Oligocene boundary. [Premoli Silva et al. 2006]
Last occurrence (top): within Priabonian Stage (33.89-37.75Ma, top in Priabonian stage). Data source: Total of range of species in this database
First occurrence (base): within Lutetian Stage (41.15-47.84Ma, base in Lutetian stage). Data source: Total of range of species in this database

Plot of occurrence data:

Primary source for this page: Premoli Silva et al. 2006 - Atlas of Eocene Planktonic Foraminifera, chapter 7, p. 170

References:

Bermudez, P.J., (1949). Tertiary smaller foraminifera of the Dominican Republic. Contributions from the Cushman Laboratory for Foraminiferal Research special publication, 25: 1-322.

Blow, W.H. & Saito, T., (1968). The morphology and taxonomy of Globigerina mexicana Cushman, 1925. Micropaleontology, 14(3): 357-360.

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, 1413 pp.

Bolli, H.M., (1972). The genus Globigerinatheka Bronnimann. Journal of Foraminiferal Research, 2(3): 109-136.

Brönnimann, P., (1952). Globigerinoita and Globigerinatheka, new genera from the Tertiary of Trinidad, B.W.I. Cushman Foundation for Foraminiferal Research, Special Publication, 3(1): 25-28.

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

Cordey, W.G., (1968). A new Eocene Cassigerinella from Florida. Palaeontology, 11: 368-370.

Cordey, W.G., (1968). Morphology and phylogeny of Orbulinoides beckmannii (Saito 1962). Palaeontology, 11(3): 371-375.

Hagn, H., (1956). Geologische und Palaontologische untersuchungen im Tertial des Monte Brione und seiner Umgebung. Palaeontographica Abt. A, 107(3-6): 173.

Loeblich, A.R., Jr. & Tappan, H., (1957). Planktonic foraminifera of Paleocene and early Eocene Age from the Gulf and Atlantic coastal plains. In: Loeblich, A.R., Jr. et al. (Editors), Studies in Foraminifera, U.S. National Museum Bulletin 215. U.S. Government Printing Office, Washington, D.C., pp. 173-198.

Loeblich, A.R. & Tappan, H., (1957). Woodringina, a new foraminiferal genus (Heterohelicidae) from the Paleocene of Alabama. Journal of the Washington Academy of Sciences., 47: 39-40.

Premoli Silva, I.; Wade, B.S. & Pearson, P.N., (2006). Taxonomy, biostratigraphy, and phylogeny of Globigerinatheka and Orbulinoides. In: Pearson, P.N. et al. (Editors), Atlas of Eocene Planktonic Foraminifera, Cushman Foundation Special Publication 41. Allen Press, Lawrence, Kansas, pp. 169-212.

Saito, T., (1962). Eocene planktonic foraminifera from Hahajima (Hillsborough Island). Trans. Proc. Pal. Soc. Japan, 1(45): 209-225.

Tappan, H., (1957). New Cretaceous index foraminifera from northern Alaska. U. S. Natl. Mus. Bull., 215: 201-222.

Toumarkine, M., (1983). Les Foraminifères planctoniques de l’Eocène moyen et supérieur des régions tropicales à temperées chaudes. PhD Thesis, Université Pierre et Marie Curie, Paris 6, 83-05, 1-219 pp.


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Globigerinatheka compiled by the pforams@mikrotax project team viewed: 18-8-2017

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