nmn

Conoglobigerina caucasica


Classification: pf_mesozoic -> Conoglobigerinidae -> Conoglobigerina -> Conoglobigerina caucasica
Sister taxa: C. caucasica, C. grigelisi, C. gulekhensis, C. helvetojurassica, C. sp.

Taxonomy

Citation: Conoglobigerina caucasica (Gorbachik & Poroshina, 1979)
Rank: Species
Basionym: Globuligerina caucasica
Taxonomic discussion: Surface of test under the binocular microscope appears smooth at X 96, when studied with the electron microscope (x 1000 and X 3000) a cancellate ornamentation is visible. Unfortunately, the specimens studied are not well enough preserved, the ornamentation being retained only in parts of the test and even there partly destroyed. Cells roughly quadrangular, separated by relatively broad, smooth ridges. The cells are 2-4 microns in size. Pores lie mainly within the cells, but single pores are observed on the ridges too. Pores round or oval, about 0.5 microns in size (tf. 3c, d). [copied from Chronos database]

Type images:

Original description: Translation from Russian: Test small, diameter no more than 0.23 mm, usually oval, concavo-convex, low trochoid, height about twice as small as the diameter. Coil made up of 2-2.5 whorls. Early chambers very small, weakly convex, oval or rounded in outline, hard to discern and only slightly surmounting the chambers of the last whorl. There are four or five of them. In the last whorl are four chambers, rapidly increasing in dimensions, relatively low, and somewhat flattend. Septal sutures depressed, slightly curved in the early chambers and nearly straight in the later ones. Peripheral margin narrow, rounded, outline of test distinctly lobate. Umbilicus small, narrow. Aperture opens into umbilicus and extends along the base of the last chambers, not reaching the peripheral margin, arcuate, fringed with a narrow, slightly expressed lip, filled with rock in the specimens studied. Wall finely perforate.

Entries in the Catalog of original descriptions: Globuligerina caucasica

Geological Range:
Last occurrence (top): within Valanginian Stage (133.88-139.39Ma, top in Valanginian stage). Data source: [copied from Chronos database]
First occurrence (base): within Berriasian Stage (139.39-145.01Ma, base in Berriasian stage). Data source: [copied from Chronos database]

Plot of range and occurrence data:

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Spiroconvexaperture:Umbilical
sp chamber shape:Globularcoiling axis:Low-moderateperiphery:N/Aaperture border:N/A
umb chbr shape:Globularumbilicus:Narrowperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Moderately depressedumb depth:Shallowwall texture:shell porosity:
umbilical or test sutures:Moderately depressedfinal-whorl chambers:4.0-5.0 N.B. These characters are used for advanced search. N/A - not applicable

References:

Gorbachik, T. N. & Poroshina, L. A. (1979). Новые планктонные фораминиферы из берриасских отложений Азербайджана [New planktonic foraminifera from the Berriasian of Azerbaijan]. Paleontologicheskiy Zhurnal. 3: 22-28. gs


logo

Conoglobigerina caucasica compiled by the pforams@mikrotax project team viewed: 22-1-2021

Taxon Search:
Advanced Search

Short stable page link: http://mikrotax.org/pforams/index.php?id=110058 Go to Archive.is to create a permanent copy of this page - citation notes



Comments (0)

No comments yet on this page. Please do add comments if you spot any problems, or have information to share

Add Comment

* Required information
1000
Captcha Image
Powered by Commentics