Taxonomy
Original description: Test trochoid, biconvex, dorsal side distinctly convex, ventral side strongly convex; periphery slightly scalloped, chambers numerous, eight or nine in final whorl, dorsal side flattened, bordered by a thickened, slightly elevated margin which curves forward from the edge of the preceding chamber to the spiral suture, chambers seen from the ventral side inflated, extended in the direction of the axis of coiling producing a deep steepsided umbilical area; sutures on the ventral side strongly depressed, curving gently backward; periphery acute, wall finely perforate; aperture umbilical at base of last chamber.
Entries in the Catalog of original descriptions: Globorotalia greenhornensis
Character matrix
test outline: | Subcircular | chamber arrangement: | Trochospiral | edge view: | - | aperture: | Umbilical-extraumbilical |
sp chamber shape: | Subtriangular | coiling axis: | Very low | periphery: | Single keel | aperture border: | Thin lip |
umb chbr shape: | Subtriangular | umbilicus: | Narrow | periph margin shape: | Subangular | accessory apertures: | Umbilical |
spiral sutures: | Raised beaded | umb depth: | Deep | wall texture: | Smooth | shell porosity: | Finely Perforate: 1-2.5µm |
umbilical or test sutures: | Moderately depressed | final-whorl chambers: | 8-9 | N.B. These characters are used for advanced search. N/A - not applicable |
Geological Range:
Last occurrence (top): within R. cushmani zone (94.03-98.69Ma, top in Cenomanian stage). Data source: [copied from Chronos database]
First occurrence (base): within R. cushmani zone (94.03-98.69Ma, base in Cenomanian stage). Data source: [copied from Chronos database]
Plot of range and occurrence data:
Eicher, D. L. & Worstell, P. (1970). Lunatriella, a Cretaceous heterohelicid foraminifer from the western interior of the United States. Micropaleontology. 16(1): 117-121. gs Falzoni, F., Petrizzo, M. R., Jenkyns, H. C., Gale, A. S. & Tsikos, H. (2016). Planktonic foraminiferal biostratigraphy and assemblage composition across the Cenomanian–Turonian boundary interval at Clot Chevalier (Vocontian Basin, SE France). Cretaceous Research. 59: 69-97. gs Leckie, M. (1984). Mid-Cretaceous planktonic foraminiferal biostratigraphy off Central Morocco, Deep Sea Drilling Project Leg 79, Sites 545 and 547. Initial Reports of the Deep Sea Drilling Project. 79: 579-620. gs Leckie, M. (1985). Foraminifera of the Cenomanian-Turonian boundary interval, Greenhorn Formation, Rock Canyon Antoicline, Pueblo, Colorado. In, Pratt, L. M., Kauffman, E. G. & Zelt, F. B. (eds) Fine-grained deposits and biofacies of the Cretaeous Wesern Interior Seaway: Evidence of cyclic sedimentary processes. SEPM Field Trip Guidebook . 4: 139-149. gs Morrow, A. L. (1934). Foraminifera and ostracoda from the Upper Cretaceous of Kansas. Journal of Paleontology. 8: 186-205. gs Pessagno, E. A. (1967). Upper Cretaceous planktonic foraminifera from the western Gulf Coastal Plain. Palaeontographica Americana. 5: 245-445. gs O Postuma, J. A. (1971). Manual of planktonic foraminifera. Elsevier for Shell Group, The Hague. 1-406. gsReferences:
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Thalmanninella greenhornensis compiled by the pforams@mikrotax project team viewed: 30-4-2025
Short stable page link: https://mikrotax.org/pforams/index.php?id=110547 Go to Archive.is to create a permanent copy of this page - citation notes |
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