Cribrohantkenina inflata


Classification: pf_cenozoic -> smooth non-spinose -> Hantkeninidae -> Cribrohantkenina -> Cribrohantkenina inflata
Sister taxa: C. inflata,

Taxonomy

Citation: Cribrohantkenina inflata Howe 1928
Rank: Species
Basionym: Hantkenina inflata
Synonyms:
Taxonomic discussion: Several species with cribrate apertural systems of varying complexity have been described, i.e., Hantkenina inflata Howe, Hantkenina mccordi Howe and Wallace, Hantkenina danvillensis Howe and Wallace, Hantkenina (Cribrohantkenina) bermudezi
Thalmann and Hantkenina lazzarii Pericoli. In our research we examined large populations of Cribrohantkenina in ODP Sites 865 and 1053 (Coxall, 2000) but were unable to distinguish any clear stratigraphical or geographical trends in this character other than the first cribrohantkeninids tend to have a single additional areal aperture. Therefore, we refer all Cribrohantkenina morphotypes to the earliest named taxon, Hantkenina inflata Howe. Serial removal of the chambers of C. inflata reveals that chambers formed earlier in ontogeny possess simple Hantkenina-type apertures, thus pre-adult C. inflata are indistinguishable from co-occurring H. nanggulanensis and H. alabamensis. This observation serves to unite the two genera as members of a closely related clade.
The additional apertures of this taxon may be circular, oval or keyhole-shaped and are usually symmetrically arranged along the equatorial plane. It is likely that they developed by invagination of the margins of a typical Hantkenina-type aperture (Bermúdez, 1937; Bandy, 1949; Barnard, 1954; Banner and Blow, 1959; Ramsay, 1962; Blow and Banner, 1962; Dieni and Proto Decima, 1964). Specimens with apertures transitional in morphology between Hantkenina and Cribrohantkenina demonstrate that the evolution involved several steps and processes: broadening of the high-arched triradiate aperture (as seen in H. nanggulanensis); crenulation and invagination of the imperforate margin; and restriction of the primary aperture, creating isolated areal opening(s) in the imperforate surround.
The precise stratigraphic range of Cribrohantkenina in the uppermost Eocene is difficult to establish in many sites because of common dissolution events associated with the Eocene/Oligocene climatic transition (e.g., Shackleton and Kennett, 1975; Zachos and others, 1996). Rare complete specimens, or more commonly fragments of the characteristic aperture system, have been found ranging up to the Eocene/ Oligocene boundary at Torre Cardela, Fuente Caldera, and Molino de Cobo, Spain; Massignano, Italy; Tanzania (PNP, unpublished data); and ODP Site 707, Indian Ocean (Martinez-Gallego and Molina, 1975; Molina, 1986; Molina and others, 1988; Coccioni, 1988; Nocchi and others, 1988; Coxall, 2000) confirming that this genus existed in parallel with Hantkenina until their apparently simultaneous extinction at the boundary. Van Eijden (1995, p. 240) figured an interesting specimen with Cribrohantkenina-like areal apertures from Zone E12. This specimen has the morphology of H. compressa, and is relatively small and compressed in comparison to the forms found in the upper Eocene. No other occurrences of Cribrohantkenina have been recorded below Zone E14, hence Van Eijden’s specimen is considered a probable teratoid Hantkenina.
An important feature of our Cribrohantkenina taxonomy is the synonomy of Cribrohantkenina lazzarii (Pericoli) with C. inflata. Cribrohantkenina lazzarii has been commonly recorded from the uppermost Eocene of Italy and Spain. It is described as differing from C. inflata in having a more polygonal peripheral outline, more compact coiling (Pericoli, 1958) and a higher stratigraphic range, extending above the last occurrence of C. inflata to the Eocene/Oligocene boundary (Dieni and Proto Decima, 1964; Coccioni, 1988; Gonzalvo and Molina, 1992). The holotype of C. lazzarii has been examined under SEM for the first time in this work. Micrograph images reveal that the holotype is crushed and very poorly preserved (Pl.8.3, Figs. 15-16), hampering recognition of the cribrate aperture and exaggerating the polygonal morphology. In our investigations of uppermost Eocene assemblages (including DSDP Site 522, ODP Sites 707, Tanzania, Torre Cardela, and Massignano) we were unable to stratigraphically or morphologically distinguish the C. lazzarii morphotype from C. inflata at any location. Furthermore we have found inflated forms of the C. inflata-type ranging up to the Eocene/Oligocene boundary at Massignano, Tanzania and in the Spanish sections. In agreement with Coccioni (1988) and Gonzalvo and Molina (1992) we recognize that some forms of Cribrohantkenina have more polygonal chambers and an angular peripheral outline. However, we observe that this feature is also characteristic of earlier stages of ontogeny in all specimens of Cribrohantkenina and that loss of the final globular chamber through breakage (which is common in upper Eocene foraminiferal assemblages from the Tethyan region) changes the overall aspect of the shell considerably by emphasizing the pre-adult polygonal form. [Coxall & Pearson 2006]

Catalog entries: Hantkenina (Cribrohantkenina) bermudezi;
Hantkenina danvillensis;
Hantkenina inflata;

Type images:

Short diagnosis: Cribrohantkenina inflata is distinguished from H. nanggulanensis and all other hantkeninids by the presence of one of more areal apertures in addition to the primary aperture in the final adult chamber(s). Forms possessing a deeply crenulated primary aperture but no isolated additional aperture (a condition that probably represents the transition from H. nanggulanensis) are excluded from the genus. This taxon contains some of the largest individuals among modern and fossil planktonic foraminifera, attaining shell sizes in excess of 1.0 mm.

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: Cribrohantkenina inflata is distinguished from H. nanggulanensis and all other hantkeninids by the presence of one of more areal apertures in addition to the primary aperture in the final adult chamber(s). Forms possessing a deeply crenulated primary aperture but no isolated additional aperture (a condition that probably represents the transition from H. nanggulanensis) are excluded from the genus. This taxon contains some of the largest individuals among modern and fossil planktonic foraminifera, attaining shell sizes in excess of 1.0 mm. [Coxall & Pearson 2006]

Wall type: Smooth, normal perforate,
probably non-spinose; tubulospines imperforate, smooth or with fine striations. [Coxall & Pearson 2006]

Test morphology: Planispiral, biumbilicate, 5-6 chambers in the final whorl increasing rapidly in size as added; chambers polygonal or spherical and laterally inflated in the adult whorl, especially the final chamber; peripheral outline lobate or angular; chambers of the adult whorl extended into a hollow tubulospine; primary aperture is an equatorial arch, low or tall and narrow, bordered by an imperforate lip, supplemented on the final 1-3 chambers by one or more (up to 16) additional areal apertures on the chamber face set in a delicate perforate apertural ‘plate’, each additional aperture surrounded by an imperforate thickened rim; sutures depressed and curved with deep restricted umbilici, pustules sometimes present in the umbilical region; tubulospines short and triangular, or long and slender, ends tapering to a point, positioned at the anterior chamber edge, spanning the suture between chambers, arising sharply from the supporting chamber and inclined forward in the direction of coiling at a low angle almost tangential with respect to the periphery in the final stages and contacting adjacent younger chambers along their outer periphery; penultimate tubulospines may be completely enveloped by globular younger chambers. [Coxall & Pearson 2006]

Size: Maximum diameter excluding tubulospines is 0.58 mm and including tubulospoines 0.75 mm (Howe, 1928). Generally large, 0.40-1.0 mm. [Coxall & Pearson 2006]

Biogeography and Palaeobiology


Geographic distribution: Worldwide, low-mid latitudes. Common at ODP Site 1053, North Atlantic, ODP Site 865, Central Pacific and coastal Tanzania. Absent from the high northern and southern hantkeninid localities such as the Labrador Sea and New Zealand. [Coxall & Pearson 2006]
Aze et al. 2011 summary: Low to middle latitudes; based on Coxall & Pearson (2006)

Isotope paleobiology: This species tends to yield low ∂18O and high ∂13C compared to other co-existing species analyzed (Poore and Matthews, 1984; Coxall and others, 2000) indicating a warm, surface mixed layer habitat. There is no size related ∂13C-enrichment trend. [Coxall & Pearson 2006]
Aze et al. 2011 ecogroup 2 - Open ocean mixed-layer tropical/subtropical, without symbionts. Based on δ13C lighter than species with symbionts; also with relatively light δ18O. Sources cited by Aze et al. 2011 (appendix S3): Wade & Pearson (2008)

Phylogenetic relations: Cribrohantkenina inflata evolved gradually from H. nanggulanensis in the late Eocene by modification and invagination of the primary aperture in the final growth stages. As in Hantkenina, there is a tendency for
specimens to become smaller and less inflated in the latest Eocene (cf. the C. lazzarii concept). [Coxall & Pearson 2006]

Biostratigraphic distribution

Geological Range:
Notes: Upper Eocene. Upper Zone E14 to the Eocene/Oligocene boundary. [Coxall & Pearson 2006]
Last occurrence (top): in mid part of E16 zone (47% up, 34.3Ma, in Priabonian stage). Data source: Eocene Atlas
First occurrence (base): within E14 zone (35.89-37.99Ma, base in Bartonian stage). Data source: Eocene Atlas

Plot of occurrence data:

Primary source for this page: Coxall & Pearson 2006 - Atlas of Eocene Planktonic Foraminifera, chapter 8, p. 226

References:

Bandy, O.L., (1949). Eocene and Oligocene foraminifera from Little Stave Creek, Clarke County, Alabama. Bulletin of American Paleontology, 32(131): 1-210.

Banner, F.T. & Blow, W.H., (1959). The classification and stratigraphical distribution of the Globigerinaceae. Paleontology, 2(1): 1-27.

Barnard, T., (1954). Hantkenina alabamensis Cushman and some related forms. Geological Magazine, 91(5): 384-390.

Bermudez, P.J., (1937). Nuevas especies de Foraminiferos del Eoceno de las cercanias de Guanajay, provincia Pinar del Rio, Cuba. Memorias de la Sociedad Cubana de Historia Natural, 11(4): 237-248.

Blow, W.H. & Banner, F.T., (1962). The mid-Tertiary (Upper Eocene to Aquitanian) Globigerinaceae. In: Eames, F.E. et al. (Editors), Fundamentals of mid-Tertiary Stratigraphical Correlation. Cambridge University Press, Cambridge, pp. 61-151.

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.

Brönnimann, P., (1950). The Genus Hantkenina Cushman in Trinidad and Barbados, B. W. I. . Journal of Paleontology, 24(4): 397-420.

Brönnimann, P., (1952). Trinidad Paleocene and lower Eocene Globigerinidae. Bulletin of American Paleontology, 34(143): 1-34.

Coccioni, R., (1988). The genera Hantkenina and Cribrohantkenina (Foraminifera) in the Massignano section (Ancona, Italy),: AnconaII, . 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, Special Publication II, pp. 81-96.

Coxall, H.K. & Pearson, P.N., (2006). Taxonomy, biostratigraphy, and phylogeny of the Hantkeninidae (Clavigerinella, Hantkenina and Cribrohantkenina). In: Pearson, P.N. et al. (Editors), Atlas of Eocene Planktonic Foraminifera, Cushman Foundation Special Publication 41. Allen Press, Lawrence, Kansas, pp. 213-256.

Coxall, H.K., (2000). Hantkeninid planktonic foraminifera and Eocene palaeoceanographic change. PhD Thesis, University of Bristol, unpublished, 264 pp.

Coxall, H.K.; Pearson, P.N.; Shackleton, N.J. & Hall, M.A., (2000). Hantkeninid depth adaptation: An evolving life strategy in a changing ocean. Geology, 28: 87-90.

Cushman, J.A., (1925). New foraminifera from the Upper Eocene of Mexico. Contributions from the Cushman Foundation for Foraminiferal Reseach, 1(1): 4-9.

Cushman, J.A., (1946). A rich foraminiferal fauna from the Cocoa sand of Alabama. Cushman Foundation for Foraminiferal Research, Special Publication, 16: 40 p.

Eijden 1995 [sorry, not in our bibliography yet]

Gallego & Molina 1975 [sorry, not in our bibliography yet]

Gonzalvo, C. & Molina, E., (1992). Bioestratigrafia y cronoestratigrafia del transito Eoceno-Oligoceno en Torre Cardela (Espana) y Massignano (Italia). Revista Espanola de Paleontologia, 7: 109-126.

Howe, H.V. & Wallace, W.E., (1932). Foraminifera of the Jackson Eocene at Danville Landing on the Ouachita, Catahoula Parish, Louisiana. Bulletin of the Geological Survey of Louisiana, 2: 1-118.

Howe, H.V. & Wallace, W.E., (1934). Apertural characteristics of the genus Hantkenina, with description of a new species. Journal of Paleontology, 8(1): 35-37.

Howe, H.V., (1928). An observation on the range of the genus Hantkenina. . Journal of Paleontology, 2(1): 13-14.

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.

Molina, E., (1986). Description and biostratigraphy of the main reference section of the Eocene/Oligocene boundary in Spain: Fuente Caldera secton. In: Pomerol, C. and Premoli-Silva, I. (Editors), Terminal Eocene Events. Elsevier Science Publishers B. V., Amsterdam, pp. 53-63.

Molina, E.; Keller, G. & Madile, M., (1988). Late Eocene to Oligocene events: Molino de Cobo, Betic Cordillera, Spain. Revista Española de Micropaleontología, 20(3): 491-514.

Nocchi, M. & others, (1988). The extinction of Hantkeninidae as a marker for defining the Eocene-Oligocene boundary: A proposal. 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, Special Publication II, pp. 81-96.

Pericoli, S., (1958). Sulla presenza del genere Hantkenina Cushman nella Scaglia dell’ Urbinate. Bollettino della Societa dei Naturalisti in Napoli, 157: 2-26.

Poore, R.Z. & Matthews, R.K., (1984). Oxygen isotope ranking of late Eocene and Oligocene planktonic foraminifers: implications for Oligocene sea-surface temperatures and global ice-volume. Marine Micropaleontology, 9: 111-134.

Proto Decima 1964 [sorry, not in our bibliography yet]

Raju, D.S.N., (1968). Eocene-Oligocene planktonic foraminiferal biostratigraphy of Cauvery Basin, South India. Geological Society of India, 2: 286-299.

Ramsay, W.R., (1962). Hantkeninidae in the Tertiary rocks of Tanganyika. Contributions from the Cushman Foundation for Foraminiferal Research, 13: 78-89.

Rey, M., (1939). Distribution stratigraphique des Hantkenina dans le Nummulitique du Rharb (Maroc). Bulletin de la Société Géologique de France, 5: 321-341.

Shackleton, N.J. & Kennett, J.P., (1975). Paleotemperature history of the Cenozoic and the initiation of Antarctic glaciation: oxygen and carbon isotope analysis in DSDP Sites 277, 279 and 281,. Initial Reports of the Deep Sea Drilling Project, 29: 881-884.

Spraul, G.L., (1963). Current status of the upper Eocene foraminiferal guide fossil, Cribrohantkenina. Journal of Paleontology, 37(2): 366-370.

Station 1640 [sorry, not in our bibliography yet]

Thalmann, H.E., (1942). Foraminiferal genus Hantkenina and its subgenera. American Journal of Science, 240: 809-820.

Zachos, J.C.; Quinn, T.M. & Salamy, K.A., (1996). High-resolution (104 years) deep-sea foraminiferal stable isotope records of the Eocene-Oligocene climate transition. Paleoceanography, 11: 251-266.


Cribrohantkenina inflata compiled by the pforams@mikrotax project team viewed: 28-6-2017

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