Gubkinella graysonensis Tappan 1940 from: Leckie, M.R. (1990): Middle Cretaceous Planktonic Foraminifers of the Antarctic Margin: Hole 693A, ODP Leg 113. In: Proceedings of the Ocean Drilling Programme Vol. 113 Eds: Parker, P.F..Kennett, J.P.O'Connell, S..Pisias, N.G. p. 319-324 . |
Notice: This catalogue page may contain unedited data.
|
Species Gubkinella graysonensis Tappan 1940 |
|
|
Discussion / Comments: |
Leckie (1990):
Distinctive compact, quadrilobate test. In adults, the
aperture is a low arch with a thin lip and is umbilical in position. In juveniles,the aperture can be more umbilical-extraumbilical in position(Pl. 1, Fig. 2). Both moderate spired (Pl. 1, Fig. 6) and high spired (Pl.1, Fig. 7) forms are observed in the material from ODP Site 693.
This long-ranging taxon is especially characteristic of neritic environments (continental margins, epicontinental seas; e.g., Tappan, 1940;Longoria, 1974) as well as areas of upwelling (e.g., Leckie, 1987). Longoria(1974) reports a lower Aptian (Leupoldina cabri Zone) first occurrence
for G. graysonensis.
Pflaumann & Krasheninnikov (1977):
Four globular chambers forming the last whorl, main aperture
low, interiomarginal, in the middle part of the last chamber. Initial
part of the spira small, acute.
The species has been recorded from upper Grayson formation,
Texas, from the Lenticulina ouachensis ouachensis Zone of Trinidad.
Longoria (1974) gave a range from late Aptian to Cenomanian. |
Systematics: |
22 Genus Gubkinella
Species Gubkinella graysonensis
|
Synonym list: |
Leckie (1990):
Pflaumann & Krasheninnikov (1977):
|
References: |
Tappan,H. (1940): Foraminifera from the Grayson Formation of northern Texas . Journal of Paleontology Vol. 14 p. 93-126
Longoria,J.F. (1974): Stratigraphic, morphologic and taxonomic studies of Aptian planktonic Foraminifera . Revista Espanola de MicropaleontologíaNo extraord p. 1-107
Pflaumann,U. and Krasheninnikov,V.. (1977): Early Cretaceous planktonic foraminifers from eastern North Atlantic, DSDP Leg 41 . In: Initial Reports of the Deep Sea Drilling Project 41 , Abidjan, Ivory Coast, to Malaga, Spain, February-April 1975 Eds: Gardner, J..Herring, J.. p. 539-564
Leckie,M.R. (1984): Mid-Cretaceous planktonic foraminiferal biostratigraphy off Morocco, Deep Sea Drilling Project Leg 79, Sites 545 and 547 . Initial Reports of the Deep Sea Drilling Project Vol. 79 p. 579–620
Leckie,M.R. (1990): Middle Cretaceous Planktonic Foraminifers of the Antarctic Margin: Hole 693A, ODP Leg 113. In: Proceedings of the Ocean Drilling Programme Vol. 113 Eds: Parker, P.F..Kennett, J.P.O'Connell, S..Pisias, N.G. p. 319-324
|
This work is licensed under a Creative Commons Attribution 2.5 License.
|
|