Catalog - Globotruncana navarroensis Catalog - Globotruncana navarroensis

CATALOG OF ORIGINAL DESCRIPTIONS: Globotruncana navarroensis Smith&Pessagno 1973

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 -> Globotruncana -> Globotruncana navarroensis
Other pages this level: << < G. lobata, G. loeblichi, G. loefgreni, G. lugeoni, G. lugeoni angulata, G. lunaris, G. marginata austinensis, G. marianosi, G. mariei, G. mayaroensis, G. mexicana, G. monmouthensis, G. morozovae, G. nakkadyi, G. naqibi, G. navarroensis, G. neotricarinata, G. orientalis, G. pessagnoi, G. postrugosa, G. poststephensoni, G. pozaryskae, G. pseudoconica, G. pseudofornicata, G. pura, G. pustulifera, G. putahensis, G. qabeliatensis, G. quadrata, G. renzi, G. repanda> >>

Globotruncana navarroensis

Citation: Globotruncana navarroensis Smith&Pessagno 1973
Taxonomic rank: species
Described on page(s) : 49-50
Type specimens: Plate 22, figures 1-3, 4-5, 6-8, 9-10; holotype 170540
Type sample (& lithostrat): Type sample TX2AA, from dark gray, conchoidal fracturing, calcareous mudstone taken from the base of quarry (as of May, 1970); Corsicana Fm.
Type age (chronostrat): Maastrichtian
Type locality: Southern clay pit of the Corsicana Brick Company, 2 miles south of the courthouse and east of the Southern Pacific Railway and Farm Road 709 (15th Street), in the southern part of Corsicana, Navarro County, TX.
Type repository: Washington; USNM

Linked specimens: USNM-170540 USNM-170541

Current identification/main database link: Contusotruncana plicata (White 1928, emended by Solakius and Salaj, 1985)


Original Description

Test trochospiral, strongly spiroconvex (mean T'X/TX value 0.079 for 13 measured specimens), umbilical side flattened, often somewhat concave; initial whorls of spiral portion of test characteristically offset to­ ward the peripheral margin due to the extremely rapid increase in size of the last three chambers; periphery sub­ circular to elongate ellipsoidal, slightly lobate, initial por­ tion truncated by umbilical1y reflected, beaded double keel which merges rapidly into a single keel in the early portion of the final whorl; chambers on spiral side initially small, globular, increasing gradually in size as added; final whorl consisting of four or five large, crescentic, slightly inflated chambers increasing rapidly in size as added; the ultimate chamber occasionally having a medial and radi­ ally orientated shallow depression; chambers umbilically subrectangular to trapezoidal, flattened to weakly inflated, increasing gradually in size as added; spiral sutures strongly curved, broadly depressed; umbilical sutures straight, radial, sharply and deeply depressed; spiral surface smooth or occasionally possessing irregularly placed coarse papil­lae, usually more abundant on the early chambers spirally; chambers umbilically smooth to finely papillate; wall finely perforate; umbilicus subrectangular, variable in width but usually rather narrow, deep; primary aperture interiomar­ ginal, umbilical; tegilla with intralaminal and infralaminal accessory apertures poorly preserved in material examined.


Size:
Holotype measures 664 µm in length, 624 µm in width, and 408 µm in maximum thickness. Topotypes vary from 412 µm to 672 µm in length; 385 µm to 496 µm in width; and 305 µm to 408 µm in maximum thickness.

Etymology:
Globotruncana navarroensis, n. sp., is named after Nav­arro County, Texas.

Extra details from original publication
Remarks.-Globotruncana navarroensis exhibits variation in shape of the periphery, convexity of the spiral surface as observed in axial view, surface ornamentation, and width of the umbilicus. Diagnostic characters of this species are (1) the strongly spiroconvex test, (2) the three ultimate chambers which increase rapidly in width, resulting in the initial spire being asymmetric and offset toward the periph­eral margin, and (3) the strongly curved, depressed spiral sutures and radial, depressed umbilical sutures.

Globotruncana navarroensis was derived from G. plummerae Gandolfi through an increase in convexity spirally and the restriction of the double keel to the initial portion of the final whorl. It differs from G. plummerae (1) by being strongly spiroconvex rather than biconvex, (2) in the asymmetric initial spire offset toward the peripheral margin, and (3) by the possession of a double keel (when present) restricted to the initial portion of the final whorl.

Globotruncana navarroensis differs from G. patellifor­mis Gandolfi (1) by generally having a more lobate equa­torial periphery, (2) by having an asymmetrically placed initial spire, and (3) by having chambers in the final whorl which spirally are crescentic to somewhat petaloid and wide, rather than crescentic and narrow.

Range: G. contusa-stuartiformis Assemblage Zone, G. gansseri Subzone, G. aegyptiaca Zonule, to upper part of R. fructicosa Zonule.

Occurrence: Globotruncana navarroensis n. sp., has been observed only from the Corsicana Formation of Texas. The specimen figured by EI-Naggar (1971a, pI. 6, fig. i) as Globotruncana sp. from the Maestrichtian Men­ dez Shale of Tampico, Mexico, is included herein, although no specimens of G. navarroensis, n. sp., were observed from the Mendez during the course of this investigation. Examination of both biostratigraphically older and younger stratigraphic units in the western Gulf Coastal Plain indicates that G. navarroensis is restricted, insofar known, to the middle Maestrichtian (G. gansseri Subzone).

References:

Smith, C. C. & Pessagno, E. A. (1973). Smith, C. C. & Pessagno, E. A. (1973). Planktonic foraminifera and stratigraphy of the Corsicana formation (Maestrichtian) North-central Texas. Cushman Foundation for Foraminiferal Research, Special Publication. 12: 1-67. Cushman Foundation for Foraminiferal Research, Special Publication. 12: 1-67. gs O


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Globotruncana navarroensis compiled by the pforams@mikrotax project team viewed: 20-6-2025

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