Globigerina calida praecalida Blow 1969 from: Blow, W.H. (1969): Late middle Eocene to Recent planktonic foraminiferal biostratigraphy. In: Proceedings of the First International Conference on Planktonic Microfossils, Geneva 1967 Vol. 1 Eds: Bronnimann, P.Renz, H.H. p. 199-422 | . |
Notice: This catalogue page may contain unedited data.
|
Subspecies Globigerina calida praecalida Blow 1969 |
|
|
|
| Diagnosis / Definition: |
Blow (1969):
Description of holotype: The moderate size test consist of about 9-10 chambers arranged in a very low trochospire with 4 chambers present in the last whorl. The chambers are inflated, not appressed, but well separated one from the other, and they do not embrace each other to any marked extent. The intercameral sutures are distinctly depressed, incised and are radial in direction both ventrally and dorsally. The umbilicus is moderately wide, open and deep. The aperture is essentially intraumbilical but shows slight asymmetry with respect to the umbilicus in the direction of the progression of the spire. The aperture is a moderately low arch with a narrow imperforate rimlike lip. The spire is low, depressed with the earlier whorls not protruding above the level of the dorsal surfaces of the later chambers. The wall is calcareous, radial hyaline [62a], distinctly hispid and with fine pores not densely scattered over the surface of the chambers; the pores do not open into distinct pits. The hispidity is most marked on the earlier chambers and the spine bases give rise to a weakly mamelonated test surface. Maximum diameter of holotype 0.35 mm. |
| Discussion / Comments: |
Blow (1969):
Remarks: G. calida praecalida differs from G. calida calida in not possessing distinct radial elongation of any of the chambers and in having a less widely open umbilicus. The aperture does not show the same degree of approach to the extraumbilical condition as
seen in G. calida calida. G. calida Praecalida usually only possesses 4 chambers in the last whorl but 421 chambers may be present; the chambers of the last whorl are not so well separated as in G. calida calida and there is no clear approach to planispirality. G. calida praecalida, like G. calida calida, possesses a coiling mode which shows a, rapidly opening spire with the later trochospire more lax in coiling than the earlier trochospire. These characters of the spire provide a ready distinction from G. praebulloides (s.l.). G. calida praecalida also differs from G. praebulloides praebulloides in possessing very globular chambers and more deeply incised dorsal and ventral intercameral sutures. Further, the wall of G. calida praecalida possesses fine pores which do not open into distinct pits, a feature which is in contradistinction to G. praebulloides (s.l.).
|
| Synonym list: |
Blow (1969):
1962 Globigerina calida Parker. - Parker : p.221 pl.1, fig.12 not pl.1, figs.9a-c, 10a-b, 11
1967 Globigerina calida Parker. - Parker : pl. 18, figs. 6a-c, 7, 8a-b, 9, 10 not figs. 11 and ?12
|
| References: |
Parker,F.L. (1962):
Planktonic foraminiferal species in Pacific sediments . Micropaleontology Vol. 8 p. 219-254
Parker,F.L. (1967):
Late Tertiary biostratigraphy (planktonic foraminifers) of tropical Indo-Pacific deep-sea cores . Bull. Am. Paleontol. Vol. 52
Blow,W.H. (1969):
Late middle Eocene to Recent planktonic foraminiferal biostratigraphy.
In: Proceedings of the First International Conference on Planktonic Microfossils, Geneva 1967 Vol. 1 Eds: Bronnimann, P.Renz, H.H. p. 199-422
|
This work is licensed under a Creative Commons Attribution 2.5 License.
|
|
Taxon Concept provided by