pforams@mikrotax - Chiloguembelina morsei pforams@mikrotax - Chiloguembelina morsei

Chiloguembelina morsei

Classification: pf_cenozoic -> Guembelitrioidea -> Chiloguembelinidae -> Chiloguembelina -> Chiloguembelina morsei
Sister taxa: C. adriatica, C. cubensis, C. andreae, C. ototara ⟩⟨ C. parallela, C. trinitatensis, C. wilcoxensis, C. crinita ⟩⟨ C. subtriangularis, C. midwayensis, C. morsei, C. sp.


Citation: Chiloguembelina morsei (Kline 1943)
taxonomic rank: Species
Basionym: Guembelina morsei
Taxonomic discussion: The gross morphology of Chiloguembelina morsei is very similar to that of Chiloguembelina midwayensis. Loeblich and Tappan (1957a) suggested that C. morsei can be distinguished from C. midwayensis sensu stricto by the former's narrower test, more globular chambers, and more deeply constricted sutures. The two taxa are most readily distinguished by the narrowness of their tests; the chambers of C. morsei expand less rapidly in breadth than those of C. midwayensis. Consequently, the periphery of the former defines a more acute angle (~50°) than that of the latter (~60°). Forms intermediate between C. morsei and C. midwayensis have been illustrated as C. midwayensis by D'Hondt (1991:173, pl. 2: figs. 13, 15). [Olsson et al. 1999]

Catalog entries: Guembelina morsei

Type images:

Distinguishing features:
Parent taxon (Chiloguembelina): Test subtriangular in outline, biserial throughout or rarely with multiserial final chambers; aperture a simple arched opening at base of the final chamber, with a narrow rim on one margin and a broad collar or flange directed toward one of the flat sides of the test, lacking an infolded margin or internal plate. Rarely with multiple apertures.
This taxon: The test biserial throughout. Sutures are distinct and depressed, initially sub-horizontal, oblique between later chambers. Successive chambers overlap, particularly in late ontogeny. Initial chambers sub-spherical, later chambers broader Wall surface with numerous small pustules, especially on early chambers. Aperture with a single distinct lateral flange.

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.


Character matrix
test outline:Triangularchamber arrangement:Biserialedge view:Equally biconvexaperture:Interiomarginal
sp chamber shape:Subrectangularcoiling axis:N/Aperiphery:N/Aaperture border:Thick flange
umb chbr shape:Subrectangularumbilicus:N/Aperiph margin shape:Moderately roundedaccessory apertures:None
spiral sutures:Moderately depressedumb depth:N/Awall texture:Moderately pustuloseshell porosity:Microperforate: <1┬Ám
umbilical or test sutures:Strongly depressedfinal-whorl chambers:2-2 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution

Low and middle latitudes (Boersma, 1984b; D'Hondt and Keller, 1991). [Olsson et al. 1999]

Isotope paleobiology
No data available. [Olsson et al. 1999]

Phylogenetic relations
Chiloguembelina morsei evolved from a Woodringina species in Zone P a (D'Hondt, 1991; Liu and Olsson, 1992). [Olsson et al. 1999]

Most likely ancestor: Woodringina hornerstownensis - at confidence level 3 (out of 5). Data source: Olsson et al. 1999 fig6, Koutsoukos 2014, fig16.
Likely descendants: Chiloguembelina midwayensis; plot with descendants

Biostratigraphic distribution

Geological Range:
Notes: Zone P a (D'Hondt, 1991) to Subzone Pic (Boersma, 1984b). [Olsson et al. 1999]
Last occurrence (top): within P1c subzone (62.6-63.9Ma, top in Danian stage). Data source: Olsson et al. 1999
First occurrence (base): within Pa zone (65.72-66Ma, base in Danian stage). Data source: Olsson et al. 1999

Plot of occurrence data:

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 91


Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. 1-252. gs


Chiloguembelina morsei compiled by the pforams@mikrotax project team viewed: 10-12-2023

Taxon Search:
Advanced Search

Short stable page link: Go to to create a permanent copy of this page - citation notes

Add Comment

* Required information
Captcha Image
Powered by Commentics


No comments yet. Be the first!