Taxonomy
Original description: Low to medium high conical test with a compact spire and 3.5–4 chambers in the last whorl. H/D ratio 0.5–1, rarely over 1. No preferred coiling direction observed. The chambers of the last whorl are large and have deeply incised sutures. Last whorl strongly embraces previous (? 2) whorls such that the earlier part of the test maybe hardly visible. Apex generally blunt, rarely pointed. Umbilical area depressed. Aperture generally a more or less symmetrical arch with lip, rarely comma-shaped. Specimens may have a small bulla over the umbilicus with one or two, low-arch apertures; it may resemble the bulla structure of Cenozoic Catapsydrax taxa. Wall microperforate, strongly pustulose; pustules form low and broken ridges that create an imperfectly reticulate pattern over the surface of the chambers.
Entries in the Catalog of original descriptions: Conoglobigerina grigelisi
Wall type: Microperforate, strongly pustulose; pustules form low and broken ridges which create an imperfectly reticulate pattern
Morphology: Low to medium high conical test with a compact spire
Size: up to 150 micron
Most likely ancestor: Globuligerina avariformis - at confidence level 2 (out of 5). Data source: Gradstein et al. (2017) p. 263.
Geological Range:
Last occurrence (top): within Early Kimmeridgian Substage (154.73-157.25Ma, top in Kimmeridgian stage). Data source: Gradstein et al. 2017
First occurrence (base): at base of Middle Oxfordian Substage (0% up, 160.8Ma, in Oxfordian stage). Data source: Gradstein et al. 2017
Plot of range and occurrence data:
Character matrix
test outline: | Lobate | chamber arrangement: | Trochospiral | edge view: | Spiroconvex | aperture: | Umbilical |
sp chamber shape: | Globular | coiling axis: | Low-moderate | periphery: | N/A | aperture border: | N/A |
umb chbr shape: | Globular | umbilicus: | Narrow | periph margin shape: | Broadly rounded | accessory apertures: | None |
spiral sutures: | Strongly depressed | umb depth: | Deep | wall texture: | Moderately pustulose | shell porosity: | - |
umbilical or test sutures: | Strongly depressed | final-whorl chambers: | 3.5-4.0 | N.B. These characters are used for advanced search. N/A - not applicable |
Gradstein, F. M. (2017a). New and emended species of Jurassic planktonic foraminifera. Swiss Journal of Palaeontology. 136(2): 161-185. gs V O Gradstein, F. M., Gale, A. S., Kopaevich, L., Waskowska, A., Grigelis, A. & Glinskikh, L. (2017b). The planktonic foraminifera of the Jurassic. Part I: material and taxonomy. Swiss Journal of Palaeontology. 136(2): 187-257. gs V OReferences:
![]() |
Conoglobigerina grigelisi compiled by the pforams@mikrotax project team viewed: 22-1-2021
Short stable page link: http://mikrotax.org/pforams/index.php?id=110585 Go to Archive.is to create a permanent copy of this page - citation notes |