Catalog - Globorotalia paniae

CATALOG OF ORIGINAL DESCRIPTIONS: Globorotalia paniae Scott et al. 1990

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 paniae
Other pages this level: << < G. nana pseudocontinuosa, G. nartanensis, G. naussi, G. neominutissima, G. nicobarica, G. nicolae, G. nicoli, G. obesa, G. occlusa, G. opima continuosa, G. opima nana, G. opima opima, G. orientalis, G. oscitans, G. palmerae, G. paniae, G. pentacamerata, G. perclara, G. perconigi, G. perforataminuta, G. pertenuis, G. petaliformis, G. planocompressa, G. planocompressa evoluta, G. planocompressa planocompressa, G. planoconica, G. planoconvexa, G. platispira, G. pliozea, G. praemargaritae, G. praemenardii> >>

Globorotalia paniae

Citation: Globorotalia paniae Scott et al. 1990
Rank: Species
Type specimens: Holotype and 17 paratypes registered as TF1633
Type sample (& lithostrat): Sample Y16/f8785
Type age (chronostrat): upper Lillburnian
Type locality: Te Pora Stream, Tokomaru Bay district, New Zealand
Type repository: Lower Hutt; N.Z Geological Survey foraminiferal collections

Current identification:


Original Description

Spiral orientation
Shell outline: Broadly elliptical to subcircular. There is a very shallow re-entrant above the aperture. Re- entrants at other chamber junctions are either very weak or absent and the outline is only partially lobulate (Fig. 50C).
Chamber packing and coiling: There are about 15-17 chambers with 5-5.5 in the outer whorl and a similar number in each of the 2 earlier whorls. Dextral coiling (26 specimens) predominates (1 sinistral).
Chamber shape: The last chamber is crescent-shaped. Its outer margin is arched and curvature is often almost symmetrical (Fig. 50 A,D). On some individuals there is a weakly convex leading section delimited by a zone of increased curvature where it merges with the main arch. The leading section of the inner margin is gently concave. The trailing section is usually longer and shows much greater curvature. Its termination is usually slightly elevated. Chambers of this type are constructed in the latter part of the outer whorl. In preceding cham- bers the trailing section of the inner margin is less elevated. The surfaces of late-formed chambers are weakly to moderately convex with curvature increasing towards the periphery. Sutures are slightly depressed. Chambers usually abut evenly but there is a tendency for the last 1-2 chambers to slightly underlap their predecessors (Fig. 50A).


Axial orientation
Shell outline: Inflated discoidal to weakly spiroconical shapes predominate. The spiral face is convex, some- times strongly (Fig. 50B). The umbilical face varies in elevation but is relatively depressed in the vicinity of the early chambers of the outer whorl. Commonly, the periphery is broadly rounded. It is subangular on a few specimens.
Outline of early whorls: Usually there is a broad dome which rises considerably above the outer whorl. A few specimens have lower rates of whorl translation and the early whorls are barely visible in the outline.
Outline of last chamber: Adjacent to the early whorls the spiral section of the outline is weakly convex. Curva- ture increases towards the periphery which is often broadly rounded. Commonly the inclination of this section corresponds with the outline of the early whorls and promotes the weakly spiroconical appearance of the shell. Curvature of the umbilical section usually exceeds that of the spiral and a weak, broad elevation may be present adjacent to the umbilicus (Fig. 50B).
Outline of earlier chambers: The extremity of the (n-1)th chamber is often just visible but most of the outline represents the (n-2)th chamber. It is slightly more inflated at the periphery (probably due to encrustation) than is the last chamber. The umbilical section of the outline is depressed and often barely elevated (Fig. 50B).
Aperture: On intact specimens the opening is very low and usually appears to be almost closed. Secondary calcification generally obscures the lip and also restricts the opening. On specimens in which the last-formed chamber(s) are missing the aperture is a low-arched opening, bordered by a thin lip.

Umbilical orientation and wall topography
Sutures are almost radially directed and depressed, although those on early chambers may be obscured by secondary deposits. The umbilicus is open but is often narrow. Chamber surfaces are convex in the direction of coiling. Elevation towards the coiling axis is conspicuous mainly on the last chamber. It is often very weak on early chambers of the outer whorl and falls away into a depressed surface adjacent to the umbilicus. Pores of moderate diameter are distributed evenly over the surface except for a wide zone at the periphery or on the immediately adjacent umbilical wall (Fig. 50B). Encrustation is heavy on umbilical surfaces of the early chambers of the outer whorl (Fig. 50F).

Size:

Etymology:

Extra details from original publication
VARIATION: Assessment is constrained by the small numbers of individuals examined (sometimes less than 5 per collection). Nearly all specimens from Mata River section (Tokomaru Bay district) coil sinistrally. Some have 5 chambers in the outer whorl. Elevation of the trailing section of the inner margins of late-formed chambers is variable. Specimens tend to have depressed umbilical faces but spiroconical form is usually very weak. Our reference of such material to Globorotalia paniae is tentative.

DISCRIMINATION: The rounded periphery (axial orientation), depressed umbilical face, and absence of rims and keels separate Globorotalia paniae from G. miotumida.
The axial profile is as weakly compressed at the periphery as in some Altonian populations of Globorotalia miozea. However, chambers in G. paniae are less elevated (umbilical side), the umbilical area is shallower, and the umbilicus is narrower. The spiral face of the shell tends to be more convex than in G. miozea.
Although some individuals of Globorotalia paniae are weakly spiroconical, compression at the periphery is never as strongly developed as in G. panda and there is no evidence of keel development.

RELATIONSHIPS: As yet no stratigraphic evidence relevant to the origin of Globorotalia paniae has been seen. Although chamber compression is weak, the flat topography of the wall suggests that G. paniae is a relatively advanced taxon. It is possibly a part of the G. praescitula plexus but may be a scituline.

DISTRIBUTION: Middle Clifdenian to lower Waiauan. The lowest record presently known is in Y16/f600 (Waiau River, Tokomaru Bay district) where it is associated with Praeorbulina glomerosa and rare specimens transitional with P. circularis. Although we have not yet found Globorotalia paniae in upper Clifdenian and lower Lillburnian collections, it occurs higher in the latter stage in Waiau River (Y16/f550) and elsewhere in the district (e.g. Y16/f89). In the Mata River section Globorotalia paniae occurs intermittently and in small numbers between Y16/f8464 and Y16/f8496 (lower Waiauan, within the zone of Fohsella peripheroacuta). This association also occurs in Y16/f147, Vl9/f124 (Mohaka River), and in V23/f6536 (Waipukurau district; southernmost occurrence of both taxa). There is one record (R17/f509; Tirua Pt) in northern Taranaki.

Editors' Notes

References:

Scott, G. H., Bishop, S. & Burt, B. J. (1990). Guide to some Neogene Globorotalids (Foraminiferida) from New Zealand. New Zealand Geological Survey, Paleontological Bulletin. 61: 1-135. gs


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Globorotalia paniae compiled by the pforams@mikrotax project team viewed: 4-12-2022

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