pforams@mikrotax - Acarinina rohri

pforams@mikrotax - Acarinina rohri pforams@mikrotax - Acarinina rohri

Acarinina rohri

Classification: pf_cenozoic -> Truncorotaloididae -> Acarinina -> Acarinina rohri
Sister taxa: << < A. interposita, A. echinata, A. pseudosubsphaerica, A. alticonica, A. soldadoensis, A. cuneicamerata, A. angulosa, A. africana, A. sibaiyaensis, A. esnehensis, A. mckannai, A. subsphaerica ⟩⟨ A. bullbrooki, A. punctocarinata, A. boudreauxi, A. rohri, A. topilensis, A. praetopilensis, A. mcgowrani, A. quetra, A. pseudotopilensis, A. wilcoxensis, A. esnaensis, A. primitiva, A. coalingensis, A. nitida, A. strabocella, A. sp.

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Postuma 1971 p233-4.JPG
Postuma 1971 p233-7.JPG

Taxonomy

Citation: Acarinina rohri (Bronnimann & Bermudez 1953)

Taxonomic rank: species

Basionym: Truncorotaloides rohri

Synonyms:

?Globigerinoides pseudodubia Bandy, 1949: 123, pl. 24, figs. 1a-c [middle Eocene, Tallahatta Fm., Little Stave Creek, Alabama].
?Globorotalia (Acarinina) pseudodubia (Bandy).—Blow, 1979:951, pl. 171: fig. 4 [middle Eocene, Zone P11, Kilwa area, Tanzania, East Africa]; pl 194: figs. 5 and 6 [middle Eocene, Zone P13, Kilwa area, Tanzania, East Africa].
Truncorotaloides rohri Brönnimann and Bermúdez, 1953:818-819, pl. 87: figs. 7-9 [middle Eocene, central Trinidad].— Bolli, Loeblich and Tappan, 1957:42, pl.10: figs. 5a-c [holotype reillustrated].—Bermúdez, 1961:1352, pl. 17: figs. 3a-b (4 figs.) [middle Eocene Zone P12, Guayabal Fm., Mexico]. —Samanta, 1970:207, pl. 3: figs. 20-21 [middle Eocene Orbulinoides beckmanni Zone, Discocyclina biofacies, Lakhpat, Cutch, western India].— Postuma, 1971:232, illustrations on p. 233 [Trinidad].— Blow, 1979:1037: pl. 195: figs. 4-9; pl. 196: figs. 1-5; pl. 206: figs. 1-7; pl. 231: figs. 1,2 (same as pl. 195: fig. 4), fig. 4 (same as pl. 195: fig. 9) [middle Eocene Zone P13, Kilwa area, Tanzania, East Africa].
Truncorotaloides rohri var. guaracaraensis Brönniman and Bermúdez, 1953:819, pl. 87, figs. 1-3 [middle Eocene, Duff Road, central Trinidad].
Truncorotaloides rohri var. piparoensis Brönniman and Bermúdez, 1953:819, pl. 87: figs. 4-6 [middle Eocene, Duff Road, central Trinidad].
Globorotalia (Acarinina) pseudodubia piparoensis (Brönnimann and Bermúdez).—Blow, 1979:953, pl. 171: figs. 5 and 6 [middle Eocene, Zone P11, Kilwa area, Tanzania, East Africa], pl 194: figs. 7-9 and pl. 195: fig. 2 [middle Eocene, Zone P13, Kilwa area, Tanzania, East Africa], pl. 231: figs. 5 and 6 (details of pl. 194, figs. 8 and 7, respectively), pl. 232: figs. 3-6 (details of pl. 194, fig. 9)].
Truncorotaloides rohri var. mayoensis Brönnimann and Bermúdez, 1953:820, pl. 87: figs. 10-12 [middle Eocene of Trinidad].—Blow, 1979:1040,, pl. 196: figs. 6-9 [middle Eocene Zone P13, Kilwa area, Tanzania]; pl. 50, figs. 7, 8 (from Blow, 1969:372-373, pl. 50, figs. 7,8 reillustrated) [same sample].
Truncorotaloides haynesi Samanta, 1970:205, pl. 3: figs. 24-25 [middle Eocene Orbulinoides beckmanni Zone, Lakhpat, India].
?Turborotalia (Acarinina) alteconica Samuel, 1972:196-7, pl. 55: figs. 1-3 [Middle Eocene Globigerapsis index zone, Borehole Sr-1, Bakony Mountains, Hungary].

Taxonomic discussion: The taxonomy of this morphotype is extremely complex and controversial. Several forms/taxa have been ascribed to, or differentiated from, this species over the past five decades. Below we attempt to reduce the complexity surrounding the rohri group to its most essential details:
1. Bronnimann and Bermúdez (1953) described rohri and differentiated three further varieties based on variation in chamber shape in the final perforate, nonspinose. whorl: guaracaraensis (rounded), mayoensis (angular) and piparoensis (subangular; intermediate between the rounded guaracaraensis and the central morphotype: rohri). In all, 21 well preserved specimens of guaracaraensis were recorded, 8 of rohri, 5 of piparoensis and only 2 of mayoensis; no discussion of stratigraphic extent of these morphotypes was presented.
2. Blow (1979, p. 951-953 and 1036-1041) differentiated the rohri complex into two distinct, but phylogenetically related groups: guaracaraensis and piparoensis were assigned to Acarinina (lacking distinct rimmed dorsal true supplementary apertures, degree of lateral angulation of chambers, degree of development of typical disjunct chambers and the organization of circumcameral/circumperipheral muriococarina typical of Truncorotaloides (as typified by rohri); while rohri and mayoensis (with the characters listed above) were placed in Truncorotaloides. The taxon guaracaraensis was placed in synonymy with Globigerinoides (vel Acarinina) pseudodubia Bandy (1949).
3. Blow (1979, p. 952-955) presented the case for derivation of rohri from Acarinina bullbrooki by way of the evolution / transition from A. pseudodubia to piparoensis: increased number of chambers in final whorl (4 to 5), gradual tendency to develop more laterally angulate and disjunct chamber geometry in last one or two chambers.
In our view a much more likely ancestor for
rohri is Acarinina topilensis, with which it shares several characters to the exclusion of A. bullbrooki, including the sinistal coiling bias, more incised sutures,
supplementary apertures and heavily muricate test. We have not differentiated from rohri the ‘transitional’ morphotypes illustrated by Blow of pseudodubia and piparoensis, preferring to illustrate the wide degree of variation we ascribe to rohri and its morphologic end- member mayoensis, which we include here in the synonymy of rohri.
The essentially neglected and rarely recognized taxon Globigerinoides pseudodubia Bandy may be a senior synonym of Acarinina rohri (for a dissenting view see Blow, 1979, p. 951 who considered it a senior synonym of G. (A.) guaracaraensis). We include this form provisionally as a questionable senior synonym of A. rohri.
The taxon Turborotalia (Acarinina) alteconica was described by Samuel (1972) as a high-spired variant of rohri. Similarly Truncorotaloides haynesi of Samanta seems to be a large, more openly coiled variant of rohri. [Berggren et al. 2006]

Catalog entries: Truncorotaloides rohri, Globigerinoides pseudodubia, Truncorotaloides haynesi, Truncorotaloides rohri guaracaraensis, Truncorotaloides rohri mayoensis, Truncorotaloides rohri piparoensis, Turborotalia (Acarinina) alteconica

Type images:

holotype: T. rohri
holotype: T. rohri
holotype: T. rohri

Distinguishing features:
Parent taxon (Acarinina): Moderate to low trochospire; chambers ovoid, usually 4-6 in final whorl.
Wall muricate with pustules on umbilical shoulders;
This taxon: Like A. topilensis but more evolute, with 5-6 chambers in final whorl, final chamber more disjunct; strongly muricate especially on the umbilical shoulders, and around the peripheral margin.

NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus.
They are being edited as the site is developed and comments on them are especially welcome.

Description

Diagnostic characters:

Acarinina rohri is distinguished by its strongly muricate test, particularly the concentration of muricae on the umbilical shoulders, and around the peripheral margin, the tendency to develop disjunct separation of chambers in stratigraphically younger forms and by the development of raised imperforate rims surrounding supplementary apertures on the later chambers on the spiral side. [Berggren et al. 2006]

Morphology:

Low trochospiral test with about 12-13 chambers in an evolute spire, 5 (less commonly 6) rounded to subangular chambers in last whorl; final chamber usually wedge-shaped and with disjunct separation from antepenultimate chamber; sutures on umbilical side weakly curved, depressed; umbilicus narrow and relatively deep; aperture an umbilical-extraumbilical arch extending towards the peripheral margin; hemispherical to wedge-shaped chambers on spiral side separated by straight to weakly recurved, depressed sutures; distinct, rimmed supplementary apertures visible at the base of the antepenultimate and final chambers, rarely visible between earlier chambers in last whorl; subrounded to truncate in edge view; chambers on both sides of test strongly muricate. [Berggren et al. 2006]

Wall type:

Densely muricate, normal perforate, nonspinose. [Berggren et al. 2006]

Size:

Maximum diameter of holotype 0.37 mm, thickness 0.22 mm. [Berggren et al. 2006]

Character matrix
test outline: Subcircular chamber arrangement: Trochospiral edge view: Planoconvex aperture: Umbilical-extraumbilical
sp chamber shape: Inflated coiling axis: Low periphery: N/A aperture border: N/A
umb chbr shape: Inflated umbilicus: Narrow periph margin shape: Moderately rounded accessory apertures: Sutural
spiral sutures: Moderately depressed umb depth: Deep wall texture: Coarsely muricate shell porosity: Finely Perforate: 1-2.5µm
umbilical or test sutures: Moderately depressed final-whorl chambers: 5-6 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution

Widely distributed in (sub)tropical areas, Caribbean, Spain, Aquitaine, North Africa, Middle East, India. [Berggren et al. 2006]
Aze et al. 2011 summary: Low latitudes; based on Berggren et al. (2006b)

Isotope paleobiology

No data available. [Berggren et al. 2006]
Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts; based on comparison with other species of the genus.

Phylogenetic relations

Evolved from Acarinina topilensis via intermediate/transitional morphotypes ascribed to the pseudubia -piparoensis group (Blow, 1979, p. 951-955). [Berggren et al. 2006]

Most likely ancestor: Acarinina topilensis - at confidence level 4 (out of 5). Data source: Berggren et al. (2006) fig9.2.

Biostratigraphic distribution

Geological Range:
Notes: Zone E10 to Zone E13. [Berggren et al. 2006]
Last occurrence (top): within E13 zone (37.99-39.97Ma, top in Bartonian stage). Data source: Eocene Atlas
First occurrence (base): in mid part of E10 zone (50% up, 42.6Ma, in Lutetian stage). Data source: Eocene Atlas

Plot of occurrence data:

Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
Taxon plotted: Acarinina rohri, synonyms included - Acarinina libyaensis; Acarinina rohri; Acarinina rohri piparoensis; Truncorotaloides rohri;
See also space-time plot :: Samples map :: Parent: Acarinina

Primary source for this page: Berggren et al. 2006 - Eocene Atlas, chap. 9, p. 312

References:

Berggren, W. A., Pearson, P. N., Huber, B. T. & Wade, B. S. (2006b). Taxonomy, biostratigraphy, and phylogeny of Eocene Acarinina. In, Pearson, P. N., Olsson, R. K., Hemleben, C., Huber, B. T. & Berggren, W. A. (eds) Atlas of Eocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication . 41(Chap 9): 257-326. gs O

Bermudez, P. J. (1961). Contribucion al estudio de las Globigerinidea de la region Caribe-Antillana (Paleoceno-Reciente). Editorial Sucre, Caracas. (3): 1119-1393. gs

Blow, W. H. (1969). Late middle Eocene to Recent planktonic foraminiferal biostratigraphy. In, Bronnimann, P. & Renz, H. H. (eds) Proceedings of the First International Conference on Planktonic Microfossils, Geneva, 1967. E J Brill, Leiden 380-381. gs

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. 2: 1-1413. gs

Brönnimann, P. & Bermudez, P. J. (1953). Truncorotaloides, a new foraminiferal genus from the Eocene of Trinidad, B.W.I. Journal of Paleontology. 27: 817-820. gs

Loeblich, A. R. & Tappan, H. (1957b). Planktonic foraminifera of Paleocene and early Eocene Age from the Gulf and Atlantic coastal plains. In, Loeblich, A. R. , Jr., Tappan, H., Beckmann, J. P., Bolli, H. M., Montanaro Gallitelli, E. & Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin . 215: 173-198. gs

Postuma, J. A. (1971). Manual of planktonic foraminifera. Elsevier for Shell Group, The Hague. 1-406. gs

Samuel, O. (1972b). Planktonic Foraminifera from the Eocene in the Bakony mountains (Hungary). Zborník geologických vied, séria Západné Karpaty. 17: 165-206. gs

Acarinina rohri compiled by the pforams@mikrotax project team viewed: 25-4-2025

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Comments (2)

Bridget Wade

Hi Jeremy, the occurrence data of rohri is using both the Eocene Truncorotaloides rohri and the Oligocene Globigerina rohri (Bolli) - which is now synonymised into tripartita

6 September 2018 09:13

Jeremy Young(UK)

thanks Bridget - I probably need to do a thorough check of the Neptune synonymies. I have corrected this one now

Jeremy

9 September 2018 06:28

test outline:	Subcircular	chamber arrangement:	Trochospiral	edge view:	Planoconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Inflated	coiling axis:	Low	periphery:	N/A	aperture border:	N/A
umb chbr shape:	Inflated	umbilicus:	Narrow	periph margin shape:	Moderately rounded	accessory apertures:	Sutural
spiral sutures:	Moderately depressed	umb depth:	Deep	wall texture:	Coarsely muricate	shell porosity:	Finely Perforate: 1-2.5µm
umbilical or test sutures:	Moderately depressed	final-whorl chambers:	5-6	N.B. These characters are used for advanced search. N/A - not applicable