Globorotalia formosa gracilis Bolli 1957 from: Bolli, H.M. (1957): The genera Globigerina and Globorotalia in the Paleocene-Lower Eocene Lizard Springs Formation of Trinidad, B.W.I . Bulletin of the U.S. National Museum Vol. 215 p. 61-82 | . |
Notice: This catalogue page may contain unedited data.
|
Subspecies Globorotalia formosa gracilis Bolli 1957 |
|
|
|
| Diagnosis / Definition: |
Bolli (1957):
Shape of test very low trochospiral, spiral side almost flat or slightly convex, umbilical side distinctly convex; equatorial periphery lobate: axial periphery angular with a faint keel ornamented with spines. Wall calcareous, perforate, surface distinctly spinose. Chambers angular, inflated; about 12, arranged in 2-2 1/2 3 whorls, the 5-6 chambers of the last whorl increasing rapidly in size. Sutures on dorsal side slightly curved to oblique, slightly depressed; on umbilical side radial, distinctly depressed. Umbilicus fairly narrow, deep, open. Aperture a low arch; interiomarginal, extraumbilical umbilical. Coiling between 90 and 100 percent dextral. Largest diameter of holotype 0.50 mm. |
| Discussion / Comments: |
Bolli (1957):
Globorotalia formosa gracilis Bolli, new species, new subspecies, differs from the related G. aequa Cushman and Renz in possessing a more distinct but thinner peripheral keel and more chambers in the last whorl. G. formosa gracilis is regarded as the ancestor of G. formosa formosa Bolli, new species, new subspecies. |
| Synonym list: |
Bolli (1957):
|
| Was used in synonym list of: |
|
|
| References: |
Bolli,H.M. (1957):
The genera Globigerina and Globorotalia in the Paleocene-Lower Eocene Lizard Springs Formation of Trinidad, B.W.I . Bulletin of the U.S. National Museum Vol. 215 p. 61-82
|
This work is licensed under a Creative Commons Attribution 2.5 License.
|
|
Taxon Concept provided by