CATALOG OF ORIGINAL DESCRIPTIONS: Globorotalia (Globorotalia) ichinosekiensis Takayanagi & Oda, in Takayanagi et al. 1976

This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.


Higher levels: pf_cat -> G -> Globorotalia (Globorotalia) -> Globorotalia (Globorotalia) ichinosekiensis
Other pages this level: G. (Globorotalia) crassula viola, G. (Globorotalia) cultrata exilis, G. (Globorotalia) hirsuta praehirsuta, G. (Globorotalia) ichinosekiensis, G. (Globorotalia) iwaiensis, G. (Globorotalia) merotumida, G. (Globorotalia) paralenguaensis, G. (Globorotalia) praefohsi, G. (Globorotalia) quasimiocenica, G. (Globorotalia) truncatulinoides pachytheca, G. (Globorotalia) tumida lata, G. (Globorotalia) tumida plesiotumida,

Globorotalia (Globorotalia) ichinosekiensis

Citation: Globorotalia (Globorotalia) ichinosekiensis Takayanagi & Oda, in Takayanagi et al. 1976
Rank: species
Type locality: southern bank of the lwai River, 200 m. downstream from the junction of the lwai and Kubo rivers. Kamikurosawa. lchinoseki City, lwate Prefecture, Japan
Type sample and level: sample IWA-25, in the Shimokurosawa Formation.
Holotype Repository: Sendai, Japan; Tohoku University Institute of Geology and Paleontology
Type & figured specimens: Holotype (IGPS 75026)

Current identification/main database link: Globoconella panda (Jenkins 1960)


Original Description
Test fairly large, low trochospiral, compressed: spiral side strongly convex, umbilical side much less convex and nearly flat to somewhat concave near umbilical region; equatorial periphery slightly lobulate, axial periphery subacute, with a thin carina; chambers strongly compressed, semicircular on spiral side, about 16 chambers arranged in three whorls; four and a half to five chambers in the last whorl, increasing fairly rapidly in size: sutures on spiral side curved. slightly depressed but narrowly limbate on later parts of test: on umbilical side nearly radial and slightly depressed: umbilicus very narrow: wall calcareous. finely perforate, surface smooth: aperture interiomarginal. umbilical-extraumbilical, a very low arch. bordered above by a small lip.

Size: Dimensions of types: Maximum diameter of holotype 0.44 mm.: thickness 0.22 mm. Unfigured paratypes range from 0.20 to 0.36 mm. in diameter.

Extra details from original publication
Remarks: Globorotalia (G.) ichinosekiensis is morphologically very close to G. (G.) margaritae Bolli and Bermudez, but it is distinguishable by having less developed carina, less compressed chambers, and on the spiral side rather broad and semicircular chambers. The last chamber of the new species does not occupy sxo large a part on the umbilical side as does that of G. (G.) margaritae. In addition, G. (G.) margaritae shows a strong inclination to left coiling. as emphasized in the original description and as has been ascertained also of Japanese materials. On the contrary. the specimens of G. (G.) ichinosekienesis are predominantly right coiling. In many respects G. (G.) ichinosekienesis is assumed to be a forerunner of G. (G. ) margaritae, in the same evolutionary stock. The present species also differs from G. (G.) hirsuta praehirsuta Blow in possessing a typically concavo-convex axial profile and more gently curved sutures on the spiral side.

Occurrence: This species is found only from a portion of the upper part of the Shimokurosawa Formation

References:

Takayanagi, Y., Takayama, T., Sakai, T., Oda, M. & Kitazato, H. (1976). Microbiostratigraphy of some Middle Miocene sequences in northern Japan. In, Takayanagi, Y. & Saito, T. (eds) Progress in micropaleontology. Micropaleontology Press, New York 356-381. gs


logo

Globorotalia (Globorotalia) ichinosekiensis compiled by the pforams@mikrotax project team viewed: 15-12-2019

Taxon Search:
Advanced Search

Short stable page link: http://mikrotax.org/pforams/index.php?id=130977 Go to Archive.is to create a permanent copy of this page - citation notes



Comments (0)

No comments yet. Be the first!

Add Comment

* Required information
1000
Captcha Image
Powered by Commentics