Catapsydrax africanus


Classification: pf_cenozoic -> spinose -> Globigerinidae -> Catapsydrax -> Catapsydrax africanus
Sister taxa: C. africanus, C. dissimilis, C. globiformis, C. howei, C. unicavus, C. sp.,

Taxonomy

Citation: Catapsydrax africanus (Blow and Banner 1962)
Rank: Species
Basionym: Globigerinita africana africanus
Synonyms:
Taxonomic discussion: The type specimen of unicavus (which is illustrated in SEM for the first time on Pl. 5.3, Figs. 1-3) is from the lower Miocene Cipero Formation of Trinidad. It is a compact form with a flat inner whorl. Bolli (1957b, p. 116) recorded the stratigraphic range of unicavus as beginning in the lower Oligocene Globigerina ampliapertura Zone. Bolli (1957b, p. 117) went on to describe the genus Globorotaloides for forms that traverse the supposedly characteristic morphologies of three genera in their ontogeny, namely a Globorotalia-like inner whorl, followed by a Globigerina-like stage where the aperture becomes umbilical, and finally a Catapsydrax-like stage with an umbilical bulla.
Comparisons of the respective holotypes of unicavus and suteri (Pl.5.3, Figs. 1-3, 9-11) reveal many similarities. Both are compact forms with a relatively flat inner whorl and a similar, cancellate wall texture, although neither is very well preserved. The two species differ mainly in the fact that suteri has a more inflated bulla. However we do not consider this an important characteristic, as it is very variable in populations, and conclude that the two specimens are conspecific, with suteri (Bolli) being a junior synonym of Catapsydrax unicavus. The status of specimens of true Globorotaloides that have been described as suteri in the literature are discussed under that genus, below.
Bronnimann (1952) described a small compact bullate species as Globigerina taroubaensis from the lower Eocene Navet Formation of Trinidad. The holotype is illustrated for the first time in SEM in Pl. 5.3, Figs. 5-7. It is very similar to the holotype of unicavus and we regard it as a possible senior synonym. However because taroubaensis has rarely been described by subsequent workers (with the notable exception of Blow, 1979, p. 1346) we recommend continuance of the unicavus name
until such time as the respective taxa can be researched in more detail in their type sections. It may well be that taroubaensis will ultimately be recognized as specifically distinct, as argued by Blow (1979).
Finlay (1939) described (without illustrating) Globigerina linaperta var. turgida. Jenkins selected and illustrated a lectotype in 1964. Blow (1969) considered the taxon valid, placing it in Globigerinita which is a microperforate genus in contrast to the normal perforate turgida. Fleisher (1974) and Krasheninnikov and Basov (1983) assigned turgida to Globorotaloides following Jenkins (1964). In our opinion the taxon is best placed in Catapsydrax due to its bulla with a single aperture. We have chosen to regard turgida and unicavus as conspecific and since unicavus was first illustrated and is a well understood taxon we prefer to use this name for nomenclatural stability.
Specimens of Catapsydrax unicavus are consistently present in middle and upper Eocene planktonic foraminiferal assemblages, but only as a minor component. Stable isotope studies (e.g. Poore and Matthews, 1984) suggest that they occupied a deep-dwelling planktonic habitat, in which population sizes were never large. We have observed considerable variability in the degree of chamber appression and bulla morphology. However, we acknowledge that future studies may well reveal more than one valid taxon within our broad concept of unicavus, especially as regards the larger, more loosely coiled morphotypes; but with the present level of understanding we can suggest no consistent way to subdivide them. [Olsson et al. 2006]

Catalog entries: Globigerinita africana africanus;

Type images:

Short diagnosis: Catapsydrax unicavus is distinguished from C. africanus by its less inflated bulla with only one infralaminal aperture and from Catapsydrax dissimilis by its small compact test and bulla with just one infralaminal aperture. Catapsydrax globiformis has a spherical-shaped test with a low, slightly inflated bulla with small circular, infralaminal apertures.

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: Catapsydrax unicavus is distinguished from C. africanus by its less inflated bulla with only one infralaminal aperture and from Catapsydrax dissimilis by its small compact test and bulla with just one infralaminal aperture. Catapsydrax globiformis has a spherical-shaped test with a low, slightly inflated bulla with small circular, infralaminal apertures. [Olsson et al. 2006]

Character matrix

test outline:Subquadratechamber arrangement:Trochospiraledge view:Equally biconvexaperture:Multiple
umb chamber shape:Inflatedcoiling axis:Highperiphery:N/Aaperture border:Thin lip
sp chbr shape:Inflatedumbilicus:Narrowperiph margin shape:Broadly roundedaccessory apertures:Sutural
umbilical or test sutures:Strongly depressedumb depth:Deepwall texture:Cancellateshell porosity:Macroperforate: >2.5µm
spiral sutures:Strongly depresseddiameter mm:0.38width mm:breadth mm:
final-whorl chambers:3.0-4.0

Biogeography and Palaeobiology


Geographic distribution: Global. [Olsson et al. 2006]
Aze et al. 2011 summary: Low to middle latitudes; based on Olsson et al. (2006c)

Isotope paleobiology: Stable isotope studies (Poore and Matthews, 1984) suggest that C. unicavus occupied a deep-dwelling planktonic habitat in which population sizes were never large. [Olsson et al. 2006]
Aze et al. 2011 ecogroup 4 - Open ocean sub-thermocline. Based on very light δ13C and very heavy δ18O. Sources cited by Aze et al. 2011 (appendix S3): Keller (1985)

Phylogenetic relations: Catapsydrax unicavus is probably derived from a subbotinid in the early Eocene by developing a bulla that extends over the umbilicus. [Olsson et al. 2006]

Biostratigraphic distribution

Geological Range:
Notes: Zone E2 to N6
Last occurrence (top): within E15 zone (34.68-35.89Ma, top in Priabonian stage). Data source: Eocene Atlas
First occurrence (base): within E13 zone (37.99-39.97Ma, base in Bartonian stage). Data source: Eocene Atlas

Plot of occurrence data:

Primary source for this page: Olsson et al. 2006 - Atlas of Eocene Planktonic Foraminifera, chapter 5, p. 70

References:

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.

Bolli, H.M., (1957). Planktonic foraminifera from the Oligocene-Miocene Cipero and Lengua formations of Trinidad, B.W.I. In: Loeblich, A.R., Jr. et al. (Editors), Studies in Foraminifera: U.S. National Museum Bulletin 215. U.S. Government Printing Office, Washington, DC, pp. 97-123.

Kireem 1983 [sorry, not in our bibliography yet]

Olsson, R.K.; Pearson, P.N. & Huber, B.T., (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene Catapsydrax, Globorotaloides, Guembelitrioides, Paragloborotalia, Parasubbotina, and Pseudoglobigerinella n. gen. In: Pearson, P.N. et al. (Editors), Atlas of Eocene Planktonic Foraminifera, Cushman Foundation Special Publication 41. Cushman Foundation Special Publication. Allen Press, Lawrence, Kansas, pp. 67-110.

Warraich, M.Y. & Ogasawara, K., (2001). Tethyan Paleocene-Eocene planktic foraminifera from the Rakhi Nala and Zinda Pir land sections of the Sulaiman Range, Pakistan. Science Reports of the Institute of Geosciences, University of Tsukuba, Section B = Geological Sciences, 22: 1-59.


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Catapsydrax africanus compiled by the pforams@mikrotax project team viewed: 24-9-2017

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