pforams@mikrotax - Subbotina hornibrooki

pforams@mikrotax - Subbotina hornibrooki pforams@mikrotax - Subbotina hornibrooki

Subbotina hornibrooki

Classification: pf_cenozoic -> Globigerinidae -> Subbotina -> Subbotina hornibrooki
Sister taxa: S. projecta, S. tecta, S. jacksonensis, S. corpulenta, S. eocaena, S. gortanii, S. crociapertura, S. yeguaensis, S. senni, S. roesnaesensis ⟩⟨ S. utilisindex, S. angiporoides, S. minima, S. linaperta, S. patagonica ⟩⟨ S. cancellata, S. hornibrooki, S. velascoensis, S. triloculinoides, S. triangularis, S. trivialis, S. sp.

Eocene_Atlas_pl06-12_fig4-9-10.jpg
Eocene_Atlas_pl06-12_fig5.jpg
Eocene_Atlas_pl06-12_fig6-8.jpg
Eocene_Atlas_pl06-12_fig11-13.jpg
Eocene_Atlas_pl06-12_fig14-16.jpg

Taxonomy

Citation: Subbotina hornibrooki (Bronnimann 1952)

taxonomic rank: Species

Basionym: Globigerina hornibrooki

Synonyms:

Globigerina hornibrooki Brönnimann, 1952:15, pl. 2: figs. 4-6 (holotype) [upper Paleocene Zone P5, Lizard Springs Fm., Trinidad].
Subbotina hornibrooki (Brönnimann).— Blow, 1979:1269, pl. 124: fig. 8 [lower Eocene Zone E5, DSDP Hole 47.2, northwest Pacific Ocean].
?Subbotina hornibrooki hornibrooki (Brönnimann).— Blow, 1979 (partim): 1269, pl. 101: fig. 7 [upper Paleocene Zone P5, DSDP Hole 47.2, northwest Pacific Ocean]. [Not pl. 124: fig. 7; pl.142: fig. 6; pl. 160: fig. 4.]
Globigerina finlayi Brönnimann, 1952:18, pl. 2: fig. 10a-c [middle Eocene Lizard Springs Fm., Trinidad].
?Globigerina bacuana Khalilov, 1956:235, pl. 3: fig. 4a-c [upper Paleocene, Maly Caucasus, Azerbaidzhan].
Not Subbotina hornibrooki (Brönnimann).—Poag and Commeau, 1995: 144, pl. 3: figs. 25, 26 [= Subbotina roesnaesensis n. sp.].

Taxonomic discussion: Subbotina hornibrooki has been misinterpreted by workers probably due to the line drawing of the holotype, which presents a generalized morphology. Bronnimann reported the wall to be finely perforate, which somewhat confuses matters. The holotype illustrated for the first time in SEM (Pl.6.12, Figs. 1-3) shows a coarsely perforate sacculifer-type wall texture that places this species in the Subbotina velascoensis group of species. Most of the specimens illustrated by Blow (1979) lack this diagnostic wall texture.
Blow noted the close affinity of Globigerina finlayi Bronnimann, which was described in the same paper as hornibrooki, and we here consider it a synonym. The holotype of Globigerina bacuana Khalilov has been viewed by WAB and questionably referred to this species. [Olsson et al. 2006]

Catalog entries: Globigerina hornibrooki, Globigerina bacuana, Globigerina finlayi

Type images:

holotype: G. hornibrooki
holotype: G. hornibrooki

Distinguishing features:
Parent taxon (Subbotina): Low trochospiral, tripartite test, with 3-4 rapidly inflating, globular chambers in final whorl. Umbilicus nearly closed by tight coiling. Wall cancellate with spines at nodes of the ridges, +/- spine collars.
This taxon: Test compact, low trochospiral with 3½ to nearly 4 globular embracing chambers in final whorl. Final chamber reduced and directed over the umbilicus. Wall texture coarsely cancellate, sacculifer-type.

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

Character matrix
test outline: Lobate chamber arrangement: Trochospiral edge view: Inequally biconvex aperture: Umbilical
sp chamber shape: Globular coiling axis: Low periphery: N/A aperture border: Thin lip
umb chbr shape: Globular umbilicus: Narrow periph margin shape: Broadly rounded accessory apertures: None
spiral sutures: Weakly depressed umb depth: Shallow wall texture: Cancellate shell porosity: Finely Perforate: 1-2.5µm
umbilical or test sutures: Moderately depressed final-whorl chambers: 3.5-4 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution

Global in low to mid latitudes. [Olsson et al. 2006]
Aze et al. 2011 summary: Low to middle latitudes; based on Olsson et al. (2006a)

Isotope paleobiology

No data available. [Olsson et al. 2006]
Aze et al. 2011 ecogroup 3 - Open ocean thermocline. Based on light _¹³C and relatively heavy _¹⁸O. Sources cited by Aze et al. 2011 (appendix S3): Coxall et al. (2000)

Phylogenetic relations

Subbotina hornibrooki belongs to the Subbotina velascoensis group of species that developed in the Paleocene from Subbotina cancellata Blow. Subbotina hornibrooki developed from Subbotina velascoensis in Zone P5 by developing a more compact test with a reduced ultimate chamber that is directed over the umbilicus. [Olsson et al. 2006]

Most likely ancestor: Subbotina velascoensis - at confidence level 0 (out of 5). Data source: Olsson et al. 2006 f6.2.
Likely descendants: Globoturborotalita bassriverensis; plot with descendants

Biostratigraphic distribution

Geological Range:
Notes: Upper Paleocene Zone P5 to Zone E4. [Olsson et al. 2006]
Last occurrence (top): within E4 zone (52.54-54.61Ma, top in Ypresian stage). Data source: Eocene Atlas
First occurrence (base): within P5 zone (55.96-57.10Ma, base in Thanetian 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: Subbotina hornibrooki, synonyms included - Subbotina hornibrooki;
See also space-time plot :: Samples map :: Parent: Subbotina

Primary source for this page: Olsson et al. 2006 - Eocene Atlas, chap. 6, p. 145

References:

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. (1952d). Trinidad Paleocene and lower Eocene Globigerinidae. Bulletins of American Paleontology. 34(143): 1-34. gs

Khalilov, D. M. (1956). 0 pelagicheskoy faune foraminifer Paleogenovykh otlozheniy Azerbaydzhana [Pelagic Foraminifera of the Paleogene Deposits of the Azerbaizhan SSR]. Trudy Instituta Geologii, Akademiya Nauk Azerbaidzhanskoi SSR. 17: 234-255. gs

Olsson, R. K., Hemleben, C., Huber, B. T. & Berggren, W. A. (2006a). Taxonomy, biostratigraphy, and phylogeny of Eocene Globigerina, Globoturborotalita, Subbotina, and Turborotalita. 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 6): 111-168. gs O

Poag, C. W. & Commeau, J. A. (1995). Paleocene to middle Miocene planktic foraminifera of the southwestern Salisbury Embayment, Virginia and Maryland: Biostratigraphy, allostratigraphy, and sequence stratigraphy. Journal of Foraminiferal Research. 25: 134-155. gs

Subbotina hornibrooki compiled by the pforams@mikrotax project team viewed: 11-10-2024

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Short stable page link: https://mikrotax.org/pforams/index.php?id=100286 Go to Archive.is to create a permanent copy of this page - citation notes

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test outline:	Lobate	chamber arrangement:	Trochospiral	edge view:	Inequally biconvex	aperture:	Umbilical
sp chamber shape:	Globular	coiling axis:	Low	periphery:	N/A	aperture border:	Thin lip
umb chbr shape:	Globular	umbilicus:	Narrow	periph margin shape:	Broadly rounded	accessory apertures:	None
spiral sutures:	Weakly depressed	umb depth:	Shallow	wall texture:	Cancellate	shell porosity:	Finely Perforate: 1-2.5µm
umbilical or test sutures:	Moderately depressed	final-whorl chambers:	3.5-4	N.B. These characters are used for advanced search. N/A - not applicable