Globigerinatheka luterbacheri


Classification: pf_cenozoic -> spinose -> Globigerinidae -> Globigerinatheka -> Globigerinatheka luterbacheri
Sister taxa: G. barri, G. curryi, G. euganea, G. index, G. korotkovi, G. kugleri, G. luterbacheri, G. mexicana, G. semiinvoluta, G. subconglobata, G. tropicalis,

Taxonomy

Citation: Globigerinatheka luterbacheri Bolli 1972
Rank: Species
Basionym: Globigerinatheka subconglobata subsp. luterbacheri
Synonyms:
Taxonomic discussion: As reported by Bolli (1972, p. 129), Cushman’s species mexicana “has been misinterpreted more than any other of the Globigerinatheka” (see the synonymy list) owing to the inadequate original description and illustrations and to the fact that specimens with different features and of much larger sizes than the holotype have been identified as mexicana, including by Cushman himself (1927). Saito (1962), in emending mexicana, regarded it as being very closely related to barri, which he interpreted as the bullate form of the former. Saito’s view was followed by Bolli (1972, p. 129) who, based on Beckmann’s observation of the original types, considered mexicana s. s. and barri as subspecies of Globigerinatheka mexicana. Bolli (1972) also included in mexicana his species kugleri, again as a subspecies of it, based on his finding intermediate forms, a view rejected here (see above). For instance, the specimen illustrated by Bolli (1972, pl. 2, fig. 5, the spiral view) as G. mexicana mexicana for its subtriangular outline is attributable to G. kugleri. Toumarkine (1978) illustrated as G. mexicana mexicana some specimens that do not possess the last large enveloping chamber and have a rather short, not flat initial spire; they may be closer to G. barri. The specimen attributed by Samanta (1970, pl. 2, figs. 20-21) to G. barri in our opinion exhibits a large last chamber that is more characteristic of G. mexicana. Blow (1979, p. 789) referred Globigerinatheka kutchensis Singh and Tewari, 1967 to G. mexicana mexicana because it possesses abortive chambers and not true bullae. Blow and Saito (1968a) regarded mexicana as synonymous with semiinvoluta, whilst Blow (1979) considered mexicana as synonymous with tropicalis. We recognise all these species as separate taxa (also see Bolli, 1972 for discussion). [Premoli Silva et al. 2006]

Catalog entries: Globigerinatheka conglobata luterbacheri;

Type images:

Short diagnosis: 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.

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: 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. [Premoli Silva et al. 2006]

Wall type: Spinose, cancellate, rather thick and coarsely perforate; pore diameter >5 mm. [Premoli Silva et al. 2006]

Test morphology: Test nearly globular, sometimes elongate, 2 to 3 whorls coiled in low trochospire, initially tight then looser, becoming streptospiral in the outer whorl; chambers inflated, increasing very slowly in the first whorl, then increasing moderately and gradually in size as added, chambers in last whorl much larger with the last two tending to hemispherical, last chamber may be smaller than penultimate one; sutures depressed, almost incised, except in the first whorl; numerous secondary apertures along the depressed sutures mainly at the intersection with the last chambers, frequently covered by more or less inflated bullae of variable size. [Premoli Silva et al. 2006]

Size: According to Toumarkine (1983), G. luterbacheri may reach a very large size, up to 0.85 mm. Maximum diameter of holotype 0.55 mm; figured paratypes, 0.4 to 0.6 mm. [Premoli Silva et al. 2006]

Character matrix

test outline:Circularcoiling axis:Lowchamber arrangement:Trochospiralumbilicus:Narrow
edge view:Equally biconvexumbilical or test sutures:Moderately depressedspiral sutures:Moderately depressedshell porosity:Macroperforate: >2.5
wall texture:Spinoseaperture:Umbilicalaperture border:N/Aaccessory apertures:Sutural
periphery:N/Aumb chamber shape:Globularsp chbr shape:Globularperiph margin shape:Broadly rounded
umb depth:Deepdiameter mm:0.55width mm:breadth mm:
final-whorl chambers:3.0-4.0

Biogeography and Palaeobiology


Geographic distribution: Low to mid latitudes. [Premoli Silva et al. 2006]
Aze et al. 2011 summary: Middle latitudes; based on Premoli Silva et al. (2006)

Isotope paleobiology: Globigerinatheka mexicana has oxygen and carbon isotopic ratios indicative of a mixed layer habitat (Boersma and others, 1987; Wade, 2004). [Premoli Silva et al. 2006]
Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts. Based on very heavy δ13C and relatively light δ18O. Sources cited by Aze et al. 2011 (appendix S3): this study

Phylogenetic relations: Bolli (1972, p. 114) stated that mexicana “branched off from G. subconglobata micra near the base of G. subconglobata subconglobata Zone (= upper part of Zone E8), while the subspecies barri and kugleri originated from mexicana s.s. in subsequent order always within the G. subconglobata subconglobata Zone”. Besides Bolli (1972), other authors (i.e., Stainforth and others, 1975; Blow, 1979; Toumarkine, 1983) all agree that mexicana appears first, followed slightly later by barri. Consequently, G. mexicana probably descended from the G. subconglobata plexus close to the E8/E9 zonal boundary. Through Zone E13, the sutures of G. mexicana become less pronounced, the final chamber more spherical and apertures semicircular to circular in outline. In uppermost Zone E13 and lowermost E14 in the western North Atlantic (ODP Site 1052), transitional forms are evident to G. semiinvoluta (Plate 7.8, Fig. 11). [Premoli Silva et al. 2006]

Biostratigraphic distribution

Geological Range:
Notes: Globigerinatheka mexicana appears in the lower middle Eocene and its first occurrence was used to identify the base of Zone P11 (=E9) sensu Stainforth and others, 1975; Blow, 1979; Toumarkine, 1983. Although the appearance of G. mexicana is poorly calibrated it seems it occurs very close to that of G. kugleri. It ranges up to the topmost part of E14. [Premoli Silva et al. 2006]
Last occurrence (top): within E15 zone (34.68-35.89Ma, top in Priabonian stage). Data source: Eocene Atlas
First occurrence (base): within E12 zone (39.97-40.40Ma, base in Bartonian stage). Data source: Eocene Atlas

Plot of occurrence data:

Primary source for this page: Premoli Silva et al. 2006 - Atlas of Eocene Planktonic Foraminifera, chapter 7, p. 191

References:

Berggren 1992 [sorry, not in our bibliography yet]

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.

Coccioni, R.; Monaco, P.; Monechi, S.; Nocchi, M. & Parisi, G., (1988). Biostratigraphy of the Eocene-Oligocene boundary at Massignano, (Ancona, Italy). In: Premoli Silva, I., Coccioni, R. and Montanari, A. (Editors), The Eocene-Oligocene Boundary in the Marche-Umbria Basin (Italy). International Subcommission on Paleogene Stratigraphy, Ancona, pp. 59-80.

Eckert, H.R., (1963). Die obereeozaen Globigerinen-Schiefer (Stadund Schimbergerschiefer) zwischen Pilatus und Schrattenfluh. Eclogae Geologicae Helvetiae, 56: 1001- 1072.

Finlay, H.J., (1939). New Zealand foraminifera: Key species in stratigraphy - no. 2. Transactions of the Royal Society of New Zealand, 69(1): 89-128.

Keijzer, F.G., (1945). Outline of the geology of the eastern part of the Province of Oriente, Cuba (E of 76° W.L.), with notes on the geology of other parts of the island. . Publicaties uit het Geographisch en uit het Mineralogisch-Geologisch Instituut der Rijksuniversiteit te Utrecht, Physiographisch-Geologische Reeks, ser. II,, 6: 1-239.

Mallory, V.S., (1959). Lower Tertiary biostratigraphy of the California Coast Ranges. . American Association of Petroleum Geologists, Tulsa, Oklahoma, 416 pp.

Nishi, H. & Chaproniere, G.C.H., (1994). Eocene-Oligocene subtropical planktonic foraminifers at Site 841,. Proceedings of the Ocean Drilling Program, Scientifc Results, 135: 245-266.

Nocchi, M.; Amici, E. & Premoli Silva, I., (1991). Planktonic foraminiferal biostratigraphy and paleoenvironmental interpretation of Paleogene faunas from the subantarctic transect, Leg 114. In: Ciesielski, P.F., Kristoffersen, Y. and al., e. (Editors), Proceedings of the Ocean Drilling Program, Scientific Results. Ocean Drilling Program, College Station, Texas, pp. 233-273.

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.

Pujol, C., (1983). Cenozoic planktonic foraminiferal biostratigraphy of the South-Western Atlantic (Rio Grande Rise): Deep Sea Drilling Project Leg 72. Initial Reports of the Deep Sea Drilling Project, 72: 623-673.

Snyder, S.W. & Waters, V.J., (1985). Cenozoic planktonic foraminiferal biostratigraphy of the Goban Spur Region, Deep Sea Drilling Project Leg 80. Initial Reports of the Deep Sea Drilling Project, 80: 439-472.

Spezzaferri 1990 [sorry, not in our bibliography yet]

Toumarkine, M., (1975). Middle and Late Eocene planktonic foraminifera from the northwestern Pacific Ocean: Leg 32 of the Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project, 32: 735-751.

Toumarkine, M., (1978). Planktonic foraminiferal biostratigraphy of the Paleogene of Sites 360 to 364 and the Neogene of Sites 362A, 363 and 364 Leg 40,. Initial Reports of the Deep Sea Drilling Project, 40: 679-721.

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.


Globigerinatheka luterbacheri compiled by the pforams@mikrotax project team viewed: 30-5-2017

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