Acarinina bullbrooki


Classification: pf_cenozoic -> muricate non-spinose -> Truncorotaloididae -> Acarinina -> Acarinina bullbrooki
Sister taxa: A. africana, A. alticonica, A. angulosa, A. aspensis, A. boudreauxi, A. bullbrooki, A. coalingensis, A. collactea, A. cuneicamerata, A. echinata, A. esnaensis, A. esnehensis, A. interposita, A. mcgowrani, A. mckannai, A. medizzai, A. nitida, A. pentacamerata, A. praetopilensis, A. primitiva, > >>

Taxonomy

Citation: Acarinina bullbrooki (Bolli 1957)
Rank: Species
Basionym: Globorotalia bullbrooki
Synonyms:
Taxonomic discussion: Subbotina (1947, p. 129, pls. 8, 9; 1953, p. 223, pl. 21) was one of the first to recognize and illustrate the plexus of late early to middle Eocene acarininids now associated with the bullbrooki and punctocarinata group. She referred a suite of specimens (pl. 21, figs. 1a-7c) to the Pliocene-Holocene taxon crassaformis. The illustrated forms would appear to be referable to A. wilcoxensis /quetra (pl. 21, figs. 1a-c) from the G. marginodentata Subzone (lower Eocene); A. decepta (pl. 21, figs. 2a-3c; see Blow, 1979, pl. 149, figs. 1-7; pl. 154 (from the lower Eocene Zone of conical globorotaliids); Acarinina bullbrooki (pl. 21, figs. 4a-c) from the Zone of conical globorotaliids; A. quetra (pl. 21, figs. 5a-c) from the lower part of the Zone of acarininids, middle Eocene; Acarinina primitiva (pl. 21, figs. 7a-c) from the upper middle Eocene Lyrolepis caucasica Beds, Zone of thin-walled pelagic foraminifera; and an apparent morozovelloidid referable to Morozovelloides crassatus (pl. 21, figs. 6a-c (from the Zone of thin-walled pelagic foraminifera [~/= Zone P14]).
The status of this taxon has long remained in limbo because of the uncertainty surrounding the generic identity of the holotype of Globorotalia bullbrooki Bolli and its uncertain relationship with Pulvinulina crassata var. densa Cushman (see discussion in Blow, 1979). Pessagno (1961) suggested that Globorotalia bullbrooki Bolli should be considered a junior synonym of densa, based on examination of the primary types at the USNM, a viewpoint accepted by Berggren (1966, 1968, 1977). Blow (1979, p. 915) noted that although he had made a cursory examination of the holotype of densa during a visit the U .S. National Museum in 1965 it was not found during a subsequent visit to the museum in May 1970 and presumed to be missing, a view seemingly confirmed in a subsequent letter to Blow from the then curator Richard Cifelli that the holotype of densa was indeed “not in our collections and I have no knowledge of it” (letter by Cifelli to Blow, 15th September 1970). Blow (1979: 915) suggested that unless the holotype was found it would be better to consider densa a nomen non conservandum, because of its similar appearance to decepta Martin, praetopilensis Blow, and pseudotopilensis Subbotina and the fact that it might be referable to either bullbrooki or any one of these three forms. Enigmatically the holotype of densa (Cushman Collection 3027) was described and redrawn only two years later by Cifelli (1972). The specimen appears to exhibit a beaded peripheral keel, hallmark of a morozovellid rather than an acarininid. Although poorly preserved, we have illustrated the holotype in SEM and have assigned it (questionably) to Morozovelloides crassatus (see Pearson and Berggren, Chapter 10, this volume).
The holotype of bullbrooki (USNM P5742) has a subangular peripheral margin and lacks a peripheral muricocarina. The paratype of bullbrooki (USNM P5743) is somewhat smaller and has a subrounded periphery in edge view. Toumarkine and Bolli have deposited a suite of specimens of bullbrooki in the Cushman Collection at the USNM from Site 313 of DSDP Leg 32 which includes individuals with muricate (but unkeeled) peripheral margins varying from angulate to subangular to subrounded, reinforcing the understanding that Bolli included a wide range of variation in his concept of bullbrooki, an interpretation which we follow here.
Blow (1979, p. 926-928) treated the taxon Acarinina decepta (Martin) in some detail, the essential features of which are listed below:
1. Acarinina decepta was interpreted as ancestral to A. matthewsae by way of intermediate morphotypes of A. nitida;
2. A. decepta is distinguished from its ancestor A. pseudotopilensis by a slight increase in the number of chambers in the last whorl, reduction in the tangential elongation of the later chambers and in having a more quadrate (as opposed to lobulate) peripheral outline;
3. The morphotypes decepta and nitida lie at the early end of the morphogenesis that leads from pseudotopilensis to matthewsae;
4. A. decepta also forms a link between A. pseudotopilensis and A. cuneicamerata;
5. A. pseudotopilensis evolved into the angulate A. topilensis without passing through a “decepta” intermediate stage; in similar fashion A. pseudotopilensis evolved into A. bullbrooki at stratigraphic levels prior to the “decepta /nitida” morphotypes;
6. The name decepta serves as a useful means of recognizing the complex of forms from which the extreme end members matthewsae and cuneicamerata differentiate from the pseudotopilensis rootstock.
Acarinina decepta was interpreted as ancestral to A. matthewsae by way of intermediate morphotypes of A. nitida;
A. decepta is distinguished from its ancestor A. pseudotopilensis by a slight increase in the number of chambers in the last whorl, reduction in the tangential elongation of the later chambers and in having a more quadrate (as opposed to lobulate) peripheral outline;
The morphotypes decepta and nitida lie at the early end of the morphogenesis that leads from pseudotopilensis to matthewsae;
A. decepta also forms a link between A. pseudotopilensis and A. cuneicamerata;
A. pseudotopilensis evolved into the angulate A. topilensis without passing through a “decepta” intermediate stage; in similar fashion A. pseudotopilensis evolved into A. bullbrooki at stratigraphic levels prior to the “decepta /nitida” morphotypes;
The name decepta serves as a useful means of recognizing the complex of forms from which the extreme end members matthewsae and cuneicamerata differentiate from the pseudotopilensis rootstock.
The various illustrations provided by Blow (1979) of the taxa cited above do point to the intermediate nature of the morphology of A. decepta. Reference to the illustrations of Martin (1943, pl. 7) and Blow (1979, pls. 149, 154) suggest closest affinities of decepta with bullbrooki (compare Blow, 1979, pl. 149, fig. 4 with Blow, 1979, pl. 155, fig. 6, for example). In this work we have included A. matthewsae as a junior synonym of A. bullbrooki. In view of the intermediate morphologies expressed in A. decepta and its enigmatic affinities we include A. decepta here provisionally as a dubious prior synonym of A. bullbrooki.
Globigerina spinuloinflata Bandy, 1949 has long been considered a junior synonym of either densa or a senior synonym of bullbrooki as Bandy (1964, p. 6) pointed out. (Re)illustration / drawing of the holotype of spinuloinflata Bandy by Cifelli (1972) shows marked similarities with bullbrooki, even though Cifelli called attention to the somewhat more rounded periphery of spinuloinflata in edge view as did Toumarkine and Bolli (1975, p. 130). We have been able to illustrate the holotype of Globigerina spinuloinflata Bandy from the Tallahatta Formation of Alabama. While it is difficult to place this form, we believe it may be conspecific with bullbrooki as Bandy proposed, in which case it could be regarded as the senior synonym. We retain bullbrooki, however, in the interests of nomenclatural stability, because in contrast to spinuloinflata, bullbrooki is a well-known form with historically consistent usage in the works of Bolli and coauthors and the holotype of spinuloinflata is not a common or central morphotype among the middle Eocene acarininids that have historically been referred to bullbrooki.
Acarinina bullbrooki is a widely used taxon in middle Eocene biostratigraphy. However, its biostratigraphic utility has been somewhat compromised by uncertainty regarding its taxonomic affinities. With the recognition that densa, decepta, and spinuloinflata cannot be definitively placed, the biostratigraphic utility of bullbrooki can now be re-established. [Eocene Atlas]

Catalog entries: Globigerina decepta;
Globigerina spinuloinflata;
Globorotalia (Acarinina) matthewsae;
Globorotalia bullbrooki;

Type images:

Short diagnosis: Acarinina bullbrooki is distinguished by its (sub)quadrate test, closely appressed and embracing chambers, rounded to subangular periphery, and weak to moderate murical concentration on the periphery. It differs from A. praetopilensis and related forms in having less incised sutures, generally smaller muricae, and by populations generally being approximately randomly coiled.

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: Acarinina bullbrooki is distinguished by its (sub)quadrate test, closely appressed and embracing chambers, rounded to subangular periphery, and weak to moderate murical concentration on the periphery. It differs from A. praetopilensis and related forms in having less incised sutures, generally smaller muricae, and by populations generally being approximately randomly coiled. [Berggren et al. 2006]

Wall type: Strongly muricate, non-spinose, normal perforate. [Berggren et al. 2006]

Test morphology: Quadrate, low-trochospiral; 4 inflated, moderately embracing, hemispherical chambers in last whorl; intercameral sutures radial, straight, depressed; umbilicus narrow to moderately wide in some (usually) younger forms, no circumumbilical rim of concentrated muricae; aperture a low, rimmed opening extending towards, but not reaching, the periphery; spiral side with lunate shaped chambers distributed in 2-2½ whorls; small, discrete opening(s) are observed rarely on well-preserved individuals; sutures weakly curved; edge view rounded to subangular; moderate marginal/peripheral concentration of muricae gives impression of pseudocarina in some instances. [Berggren et al. 2006]

Size: Maximum diameter of holotype 0.43 mm, thickness 0.32 mm. [Berggren et al. 2006]

Character matrix

test outline:Quadratecoiling axis:Lowchamber arrangement:Trochospiralumbilicus:Wide
edge view:Inequally biconvexumbilical or test sutures:Strongly depressedspiral sutures:Weakly depressedshell porosity:Finely Perforate: 1-2.5
wall texture:Coarsely muricateaperture:Umb.-extraumbilicalaperture border:Thin lipaccessory apertures:None
periphery:N/Aumb chamber shape:Inflatedsp chbr shape:Inflatedperiph margin shape:Moderately rounded
umb depth:Deepdiameter mm:0.43width mm:breadth mm:0.32
final-whorl chambers:4.0-4.0

Biogeography and Palaeobiology


Geographic distribution: Cosmopolitan distribution (see synomy above). [Berggren et al. 2006]
Aze et al. 2011 summary: Cosmopolitan; based on Berggren et al. (2006b)

Isotope paleobiology: Boersma and others (1987) and Pearson and others (1993, 2001) record this species as having isotope ratios indicative of a surface mixed layer habitat. [Berggren 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): Boersma (1984); Pearson et al. (1993, 2001a)

Phylogenetic relations: Probably evolved from A. boudreauxi (in Zone E7). [Berggren et al. 2006]

Biostratigraphic distribution

Geological Range:
Notes: Zone E7 to Zone E11. [Berggren et al. 2006]
Last occurrence (top): within E11 zone (40.40-41.89Ma, top in Bartonian stage). Data source: Eocene Atlas
First occurrence (base): within E7 zone (45.72-50.20Ma, base in Ypresian stage). Data source: Eocene Atlas

Plot of occurrence data:

Primary source for this page: Berggren et al. 2006 - Atlas of Eocene Planktonic Foraminifera, chapter 9, p. 269

References:

Aubert, J., (1962). Les Globorotalia de la region prerifaine (Maroc septentrional). Notes et Memoires du Service Geologique Maroc, 22: 1-156.

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

Bandy, O.L., (1964). Cenozoic planktonic foraminiferal zonation. Micropaleontology, 10: 1-17.

Berggren, W.A., (1966). ПРОБЛЕМЫ ТАКСОНОМИИ И ФИЛОГЕНЕТИЧЕСКИХ ОТНОШЕНИЙ НЕКОТОРЫХ ТРЕТИЧНЫХ ПЛАНКТОННЫХ ФОРАМИНИФЕР. USSR Academy of Sciences, 10: 309 - 332.

Berggren, W.A., (1977). Atlas of Palaeogene Planktonic Foraminifera: some Species of the Genera Subbotina, Planorotalites, Morozovella, Acarinina and Truncorotaloides. In: Ramsay, A.T.S. (Editor), Oceanic Micropaleontology. Academic Press, London, pp. 205-300.

Berggren 1992 [sorry, not in our bibliography yet]

Berggren, W.A.; Pearson, P.N.; Huber, B.T. & Wade, B.S., (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene Acarinina. In: Pearson, P.N. et al. (Editors), Atlas of Eocene Planktonic Foraminifera, Cushman Foundation Special Publication 41. Allen Press, Lawrence, Kansas, pp. 257-326.

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., (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., (1957). Planktonic foraminifera from the Eocene Navet and San Fernando formations of Trinidad. 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. 155-172.

Cushman, J.A. & Barksdale, J.D., (1930). Eocene foraminifera from Martinez, California. Contributions Department of Geology, Stanford University, 1: 55-73.

Cushman, J.A. & Renz, H.H., (1948). Eocene foraminifera of the Navet and Hospital Hill Formations of Trinidad, B.W.I. Cushman Laboratory for Foraminiferal Research, Special Publication, 24: 1-42.

Cushman, J.A., (1925). An Eocene fauna from the Moctezuma River, Mexico. Bulletin of the American Association of Petroleum Geologists, 9(2): 298-301.

Cushman, J.A., (1939). Eocene foraminifera from submarine cores off the eastern coast of North America: . Contributions from the Cushman Laboratory for Foraminiferal Research, 15: 49-76.

Galloway, J.J. & Wissler, S.G., (1927). Pleistocene foraminifera from the Lomita Quarry, Palos Verdes Hills, California. Journal of Paleontology, 1(1): 35-87.

Hamilton, E.L. & Rex, R.W., (1959). Lower Eocene phosphatized Globigerina ooze from Sylvania Guyot. U. S. Geological Survey Professional Paper, 260-W: 785-798.

Huber, B.T., (1991). Paleogene and early Neogene planktonic foraminifer biostratigraphy of ODP Leg 119 Sites 738 and 744, Kerguelen Plateau (southern Indian Ocean). Proceedings of the Ocean Drilling Program, Scientific Results, 119: 427-449.

Jenkins, D.G., (1971). New Zealand Cenozoic Planktonic Foraminifera. New Zealand Geological Survey, Paleontological Bulletin, 42: 1-278.

Martin 1943 [sorry, not in our bibliography yet]

Pearson, P.N. & others, (2004). Paleogene and Cretaceous sediment cores from the Kilwa and Lindi areas of coastal Tanzania: Tanzania Drilling Project Sites 1–5. Journal of African Earth Sciences, 39: 25-62.

Pessagno, E.A., Jr., (1960). Stratigraphy and micorpaleontology of the Cretaceous and lower Tertiary of Puerto Rico. Micropaleontology, 6(1): 87-110.

Pessagno, E.A., Jr., (1961). The micropaleontology and biostratigraphy of the middle Eocene Jacaguas group, Puerto Rico. Micropaleontology, 7(3): 351-358.

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

Todd, R. & Low, D., (1960). Smaller foraminifera from Eniwetok drill hole. U.S. Geological Survey Professional Paper, 260-x: 799-861.

Toumarkine, M. & Bolli, H.M., (1975). Foraminifères planktoniques de l'Eocène moyen et supérieur de la coupe de Possagno. Schweiz. Palaontol. Abh., 97: 69-185.


Acarinina bullbrooki compiled by the pforams@mikrotax project team viewed: 29-5-2017

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